From 9eed051916ccfe195be689de0a7148f99215c114 Mon Sep 17 00:00:00 2001
From: yiekheng <yiekheng@04080616.xyz>
Date: Mon, 4 May 2026 09:26:11 +0800
Subject: [PATCH] feat(web,api): row-level search, more sort columns, copy
 buttons
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Three operator-quality-of-life features behind the same caching and
pagination contract that the existing tables already use:

- Search bar on /acc and /users (Find/Enter to apply, Clear to reset).
  Backed by a new `q` API param that filters via WHERE
  username/f_username LIKE 'q%' on both rows + count queries so the
  table header total stays consistent under a filter.
- Two more sortable columns: acc.status and user.t_username. Sort
  columns are whitelisted because sort_col is f-string'd into ORDER
  BY (parameterised binding doesn't apply to column names) — anything
  outside the allowed set falls back to the table's default.
- Copy button on every row that writes a multi-line credentials
  message to the clipboard. New lib/clipboard.ts helper tries
  navigator.clipboard.writeText() first and falls back to
  textarea+execCommand("copy") so it works over the internal-network
  HTTP deploy where the modern API is gated by secure-context rules.
  Acc message: Username/Password (+Link if set). User message:
  From/To username and password.

Also: inactive sort indicators now render ↓ (the direction they'll
sort on first click) instead of the more ambiguous ↕.

Test suite grows from 53 to 70: tests/test_user_search_filter.py
(9 tests) pins the q-filter contract on both /user/ and /acc/;
tests/test_sort_whitelist.py (8 tests) pins the allowed sort columns
and proves out-of-set values cannot reach the SQL parser.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 app/cm_api.py                     |  45 +++--
 tests/test_sort_whitelist.py      | 153 ++++++++++++++++
 tests/test_user_search_filter.py  | 214 ++++++++++++++++++++++
 web/components/accounts-table.tsx | 283 ++++++++++++++++++++++++++----
 web/components/users-table.tsx    | 217 +++++++++++++++++++++--
 web/lib/api.ts                    |  32 ++--
 web/lib/clipboard.ts              |  46 +++++
 7 files changed, 921 insertions(+), 69 deletions(-)
 create mode 100644 tests/test_sort_whitelist.py
 create mode 100644 tests/test_user_search_filter.py
 create mode 100644 web/lib/clipboard.ts

diff --git a/app/cm_api.py b/app/cm_api.py
index b8f25f7..095f8f2 100644
--- a/app/cm_api.py
+++ b/app/cm_api.py
@@ -106,29 +106,40 @@ class CM_API:
             except (TypeError, ValueError):
                 return jsonify({"error": "limit and offset must be integers"}), 400
             prefix = (request.args.get('prefix') or '').strip()
+            # `q` is the user-facing search filter (WHERE), distinct from
+            # `prefix` which is the deployment tenant boost (ORDER BY).
+            q = (request.args.get('q') or '').strip()
+            sort_arg = request.args.get('sort', 'username')
+            # Whitelist the sort column (see /user/ for rationale).
+            sort_col = sort_arg if sort_arg in ('username', 'status') else 'username'
             # Whitelist direction so it's safe to interpolate into the
             # ORDER BY clause (parameterised binding doesn't apply to
             # column names or sort directions).
             direction = 'ASC' if request.args.get('dir', 'desc').lower() == 'asc' else 'DESC'
 
+            where_sql = "WHERE username LIKE %s" if q else ""
+            where_params = [f"{q}%"] if q else []
+
             if prefix:
                 query = (
                     "SELECT username, password, status, link FROM acc "
+                    f"{where_sql} "
                     "ORDER BY (CASE WHEN username LIKE %s THEN 0 ELSE 1 END), "
-                    f"username {direction} "
+                    f"{sort_col} {direction} "
                     "LIMIT %s OFFSET %s"
                 )
-                params = [f"{prefix}%", limit, offset]
+                params = [*where_params, f"{prefix}%", limit, offset]
             else:
                 query = (
                     "SELECT username, password, status, link FROM acc "
-                    f"ORDER BY username {direction} "
+                    f"{where_sql} "
+                    f"ORDER BY {sort_col} {direction} "
                     "LIMIT %s OFFSET %s"
                 )
-                params = [limit, offset]
+                params = [*where_params, limit, offset]
 
             rows = db.query(query, params)
-            count_rows = db.query("SELECT COUNT(*) AS c FROM acc", [])
+            count_rows = db.query(f"SELECT COUNT(*) AS c FROM acc {where_sql}", where_params)
             total = int(count_rows[0]["c"]) if count_rows else 0
             return jsonify({"rows": rows, "total": total})
 
@@ -152,30 +163,42 @@ class CM_API:
             except (TypeError, ValueError):
                 return jsonify({"error": "limit and offset must be integers"}), 400
             prefix = (request.args.get('prefix') or '').strip()
+            # `q` is the user-facing search filter (WHERE), distinct from
+            # `prefix` which is the deployment tenant boost (ORDER BY).
+            # Both can be active at once — search refines what the
+            # tenant prefix already promotes.
+            q = (request.args.get('q') or '').strip()
             sort_arg = request.args.get('sort', 'last_update_time')
-            sort_col = 'f_username' if sort_arg == 'f_username' else 'last_update_time'
+            # Whitelist the sort column — `sort_col` is f-string'd into
+            # the ORDER BY clause, which can't be parameterised. Anything
+            # outside the allowed set falls back to the default so a
+            # malformed query never hits the SQL parser unsanitised.
+            sort_col = sort_arg if sort_arg in ('f_username', 't_username', 'last_update_time') else 'last_update_time'
             direction = 'ASC' if request.args.get('dir', 'desc').lower() == 'asc' else 'DESC'
 
+            where_sql = "WHERE f_username LIKE %s" if q else ""
+            where_params = [f"{q}%"] if q else []
+
             if prefix:
                 query = (
                     "SELECT f_username, f_password, t_username, t_password, last_update_time "
-                    "FROM user "
+                    f"FROM user {where_sql} "
                     "ORDER BY (CASE WHEN f_username LIKE %s THEN 0 ELSE 1 END), "
                     f"{sort_col} {direction} "
                     "LIMIT %s OFFSET %s"
                 )
-                params = [f"{prefix}%", limit, offset]
+                params = [*where_params, f"{prefix}%", limit, offset]
             else:
                 query = (
                     "SELECT f_username, f_password, t_username, t_password, last_update_time "
-                    "FROM user "
+                    f"FROM user {where_sql} "
                     f"ORDER BY {sort_col} {direction} "
                     "LIMIT %s OFFSET %s"
                 )
-                params = [limit, offset]
+                params = [*where_params, limit, offset]
 
             rows = db.query(query, params)
-            count_rows = db.query("SELECT COUNT(*) AS c FROM user", [])
+            count_rows = db.query(f"SELECT COUNT(*) AS c FROM user {where_sql}", where_params)
             total = int(count_rows[0]["c"]) if count_rows else 0
             return jsonify({"rows": rows, "total": total})
 
diff --git a/tests/test_sort_whitelist.py b/tests/test_sort_whitelist.py
new file mode 100644
index 0000000..3658b47
--- /dev/null
+++ b/tests/test_sort_whitelist.py
@@ -0,0 +1,153 @@
+"""Tests for the `sort` parameter whitelist on /user/ and /acc/.
+
+`sort_col` is f-string-interpolated into ORDER BY (parameterised
+binding doesn't apply to column names), so an unsanitised value would
+be a SQL injection vector. The whitelist is the safety boundary —
+these tests pin both the allowed-values matrix AND the safe fallback
+for any out-of-set value.
+
+Allowed sort columns:
+  /user/   → f_username, t_username, last_update_time
+  /acc/    → username, status
+
+Out-of-set values must fall back to the table's default sort column,
+NEVER appear in the SQL.
+"""
+
+import unittest
+from unittest import mock
+
+
+def _make_client(query_responder):
+    db_patcher = mock.patch("app.cm_api.DB")
+    verify_patcher = mock.patch("app.cm_api.verify_tables_once")
+    mock_db_class = db_patcher.start()
+    verify_patcher.start()
+
+    mock_db = mock.Mock()
+    mock_db.query.side_effect = query_responder
+    mock_db_class.return_value = mock_db
+
+    from app.cm_api import create_app
+    app = create_app()
+    app.testing = True
+    return app.test_client()
+
+
+def _capture(calls):
+    """Responder that records every (sql, params) call and returns
+    plausible empty results."""
+    def responder(sql, params):
+        calls.append((sql, list(params)))
+        if "COUNT(*)" in sql:
+            return [{"c": 0}]
+        return []
+    return responder
+
+
+def _rows_query(calls):
+    """Pick out the rows SELECT (the one with LIMIT/OFFSET, not the
+    COUNT query). Fails the test if not exactly one is found."""
+    rows = [c for c in calls if "COUNT(*)" not in c[0]]
+    assert len(rows) == 1, f"expected 1 rows query, got {len(rows)}"
+    return rows[0]
+
+
+class UserSortWhitelistTests(unittest.TestCase):
+    def tearDown(self):
+        mock.patch.stopall()
+
+    def test_t_username_sort_routes_into_order_by(self):
+        # The whole point of this change — t_username is now an
+        # accepted sort column for the user listing.
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/user/?sort=t_username")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY t_username", sql,
+                      f"sort=t_username should produce 'ORDER BY t_username', got: {sql!r}")
+
+    def test_f_username_sort_still_works(self):
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/user/?sort=f_username")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY f_username", sql)
+
+    def test_default_sort_is_last_update_time(self):
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/user/")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY last_update_time", sql)
+
+    def test_unknown_sort_falls_back_to_default_not_user_input(self):
+        # Critical: if a malicious or buggy client passes
+        # ?sort=DROP TABLE users--, we MUST NOT see that string in
+        # the SQL. Whitelist falls back to last_update_time.
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/user/?sort=DROP+TABLE+users--")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY last_update_time", sql)
+        self.assertNotIn("DROP", sql.upper())
+
+
+class AccSortWhitelistTests(unittest.TestCase):
+    def tearDown(self):
+        mock.patch.stopall()
+
+    def test_status_sort_routes_into_order_by(self):
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/acc/?sort=status")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY status", sql,
+                      f"sort=status should produce 'ORDER BY status', got: {sql!r}")
+
+    def test_username_sort_still_works(self):
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/acc/?sort=username")
+
+        sql, _ = _rows_query(calls)
+        # `username` appears in the SELECT too — pin specifically the
+        # ORDER BY clause occurrence.
+        self.assertIn("ORDER BY username", sql)
+
+    def test_default_sort_is_username(self):
+        # Pre-change behaviour: /acc/ always sorted by username. After
+        # adding the whitelist, the default must remain username so
+        # callers that don't pass `sort=` see no behaviour change.
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/acc/")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY username", sql)
+
+    def test_unknown_sort_falls_back_to_username(self):
+        calls = []
+        client = _make_client(_capture(calls))
+
+        client.get("/acc/?sort=evil_column")
+
+        sql, _ = _rows_query(calls)
+        self.assertIn("ORDER BY username", sql)
+        self.assertNotIn("evil_column", sql)
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/tests/test_user_search_filter.py b/tests/test_user_search_filter.py
new file mode 100644
index 0000000..92f1833
--- /dev/null
+++ b/tests/test_user_search_filter.py
@@ -0,0 +1,214 @@
+"""Tests for the `q` search filter on /user/ and /acc/ in app.cm_api.
+
+`q` is the user-facing search parameter; `prefix` is the deployment
+tenant boost. Both can be active at once but they affect the SQL
+differently:
+  - q       → WHERE [col] LIKE 'q%'        (filters which rows return)
+  - prefix  → ORDER BY ... CASE WHEN ...   (boosts matching rows to top)
+
+These tests pin three behaviors that an operator would notice if broken:
+  1. The `total` count must respect the same WHERE as the row query
+     (otherwise "Showing 5 of 200" displays under a filter that only
+     matched 5 rows — confusing).
+  2. Empty/whitespace `q` must NOT add a WHERE clause (regression risk:
+     "WHERE [col] LIKE '%'" is fine but "WHERE [col] LIKE ''"
+     would return zero rows).
+  3. `q` and `prefix` must coexist — search refines what tenant boosts.
+
+Both /user/ (filters on f_username) and /acc/ (filters on username)
+share the same pattern, so the test classes mirror each other.
+"""
+
+import unittest
+from unittest import mock
+
+
+def _make_client(query_responder):
+    """Build a Flask test client with a custom DB.query() responder.
+
+    `query_responder(sql, params) -> list[dict]` is called for every
+    db.query() so tests can route count vs. row queries and inspect
+    SQL/params per call.
+    """
+    db_patcher = mock.patch("app.cm_api.DB")
+    verify_patcher = mock.patch("app.cm_api.verify_tables_once")
+    mock_db_class = db_patcher.start()
+    verify_patcher.start()
+
+    mock_db = mock.Mock()
+    mock_db.query.side_effect = query_responder
+    mock_db_class.return_value = mock_db
+
+    from app.cm_api import create_app
+    app = create_app()
+    app.testing = True
+    return app.test_client(), mock_db, (db_patcher, verify_patcher)
+
+
+class UserSearchFilterTests(unittest.TestCase):
+    def tearDown(self):
+        mock.patch.stopall()
+
+    def _route(self, calls):
+        """Return a query_responder that records calls and returns
+        plausible empty results. Forces every test to inspect the
+        calls list rather than the response body."""
+        def responder(sql, params):
+            calls.append((sql, list(params)))
+            if "COUNT(*)" in sql:
+                return [{"c": 0}]
+            return []
+        return responder
+
+    def test_q_param_adds_where_clause_with_starts_with(self):
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/user/?q=13c45")
+
+        # Both queries should have the WHERE clause + same params.
+        self.assertEqual(len(calls), 2, f"expected count + rows queries, got {len(calls)}")
+        for sql, params in calls:
+            self.assertIn("WHERE f_username LIKE", sql,
+                          f"missing WHERE on query: {sql!r}")
+            # Search uses 'starts with' matching → trailing '%' only
+            self.assertEqual(params[0], "13c45%",
+                             f"search param should be 'q%', got {params[0]!r}")
+
+    def test_count_query_respects_q_filter(self):
+        # If the count query doesn't filter, the UI shows "Showing 3 of
+        # 200" when the filtered total is actually 3 — confusing the
+        # operator. Pin that count and rows use the same WHERE.
+        count_calls = []
+        def responder(sql, params):
+            if "COUNT(*)" in sql:
+                count_calls.append((sql, list(params)))
+                return [{"c": 7}]
+            return []
+
+        client, _, _ = _make_client(responder)
+        client.get("/user/?q=13c4")
+
+        self.assertEqual(len(count_calls), 1)
+        sql, params = count_calls[0]
+        self.assertIn("WHERE f_username LIKE", sql)
+        self.assertEqual(params, ["13c4%"])
+
+    def test_no_q_means_no_where_clause(self):
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/user/")
+
+        self.assertEqual(len(calls), 2)
+        for sql, _ in calls:
+            self.assertNotIn("WHERE f_username LIKE", sql,
+                             f"unexpected WHERE on query: {sql!r}")
+
+    def test_whitespace_only_q_is_treated_as_no_filter(self):
+        # Operators sometimes accidentally type a space in the search
+        # box. " " or "" should NOT generate "WHERE f_username LIKE ' %'"
+        # — that filter would surprise nobody by returning 0 rows.
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/user/?q=%20%20")  # URL-encoded "  "
+
+        self.assertEqual(len(calls), 2)
+        for sql, _ in calls:
+            self.assertNotIn("WHERE f_username LIKE", sql)
+
+    def test_q_and_prefix_coexist(self):
+        # `q` filters via WHERE; `prefix` promotes via ORDER BY CASE.
+        # When both are present, the rows query has BOTH a WHERE
+        # parameter and a CASE-WHEN parameter (the prefix appears as
+        # the first ORDER BY arg). Pin the parameter ordering so a
+        # future SQL refactor can't accidentally swap them.
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/user/?q=13c4&prefix=13c")
+
+        # Find the rows query (the one with LIMIT/OFFSET, not COUNT).
+        rows_calls = [c for c in calls if "COUNT(*)" not in c[0]]
+        self.assertEqual(len(rows_calls), 1)
+        sql, params = rows_calls[0]
+        self.assertIn("WHERE f_username LIKE", sql)
+        self.assertIn("CASE WHEN f_username LIKE", sql)
+        # Order: [where_param, prefix_param, limit, offset]
+        self.assertEqual(params[0], "13c4%", "WHERE param must come first")
+        self.assertEqual(params[1], "13c%", "prefix CASE param must come after WHERE")
+
+
+class AccSearchFilterTests(unittest.TestCase):
+    """Mirror of UserSearchFilterTests for /acc/. The acc table filters
+    on `username` (not `f_username`) but the contract is otherwise
+    identical."""
+
+    def tearDown(self):
+        mock.patch.stopall()
+
+    def _route(self, calls):
+        def responder(sql, params):
+            calls.append((sql, list(params)))
+            if "COUNT(*)" in sql:
+                return [{"c": 0}]
+            return []
+        return responder
+
+    def test_q_param_adds_where_clause_with_starts_with(self):
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/acc/?q=13c45")
+
+        self.assertEqual(len(calls), 2)
+        for sql, params in calls:
+            self.assertIn("WHERE username LIKE", sql,
+                          f"missing WHERE on query: {sql!r}")
+            self.assertEqual(params[0], "13c45%",
+                             f"search param should be 'q%', got {params[0]!r}")
+
+    def test_count_query_respects_q_filter(self):
+        count_calls = []
+        def responder(sql, params):
+            if "COUNT(*)" in sql:
+                count_calls.append((sql, list(params)))
+                return [{"c": 7}]
+            return []
+
+        client, _, _ = _make_client(responder)
+        client.get("/acc/?q=13c4")
+
+        self.assertEqual(len(count_calls), 1)
+        sql, params = count_calls[0]
+        self.assertIn("WHERE username LIKE", sql)
+        self.assertEqual(params, ["13c4%"])
+
+    def test_no_q_means_no_where_clause(self):
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/acc/")
+
+        self.assertEqual(len(calls), 2)
+        for sql, _ in calls:
+            self.assertNotIn("WHERE username LIKE", sql)
+
+    def test_q_and_prefix_coexist(self):
+        calls = []
+        client, _, _ = _make_client(self._route(calls))
+
+        client.get("/acc/?q=13c4&prefix=13c")
+
+        rows_calls = [c for c in calls if "COUNT(*)" not in c[0]]
+        self.assertEqual(len(rows_calls), 1)
+        sql, params = rows_calls[0]
+        self.assertIn("WHERE username LIKE", sql)
+        self.assertIn("CASE WHEN username LIKE", sql)
+        self.assertEqual(params[0], "13c4%", "WHERE param must come first")
+        self.assertEqual(params[1], "13c%", "prefix CASE param must come after WHERE")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/web/components/accounts-table.tsx b/web/components/accounts-table.tsx
index 9693db7..3fae239 100644
--- a/web/components/accounts-table.tsx
+++ b/web/components/accounts-table.tsx
@@ -12,6 +12,7 @@ import EditableCell from "./editable-cell";
 import ConfirmDialog from "./confirm-dialog";
 import CreateAccountDialog from "./create-account-dialog";
 import Toast, { type ToastMessage } from "./toast";
+import { copyToClipboard } from "@/lib/clipboard";
 
 type Props = {
   initial: Acc[];
@@ -20,6 +21,7 @@ type Props = {
   prefixPattern: string;
 };
 type SortDir = "asc" | "desc";
+type SortKey = "username" | "status";
 type OptimisticPatch = { username: string; field: keyof Acc; value: string };
 
 function StatusBadge({ status }: { status: string }) {
@@ -59,12 +61,45 @@ function DeleteButton({
   );
 }
 
+function CopyButton({
+  label,
+  onClick,
+}: {
+  label: string;
+  onClick: () => void;
+}) {
+  return (
+    <button
+      type="button"
+      onClick={onClick}
+      aria-label={`Copy credentials for ${label}`}
+      title="Copy username and password"
+      className="inline-flex h-7 w-7 items-center justify-center rounded-md text-zinc-400 transition-colors hover:bg-zinc-100 hover:text-zinc-700 focus:outline-none focus-visible:ring-2 focus-visible:ring-zinc-400"
+    >
+      <svg
+        aria-hidden="true"
+        viewBox="0 0 16 16"
+        fill="none"
+        stroke="currentColor"
+        strokeWidth="1.5"
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        className="h-4 w-4"
+      >
+        <rect x="5.5" y="5.5" width="8" height="8" rx="1.25" />
+        <path d="M3 10.5V3.5A1 1 0 0 1 4 2.5h7" />
+      </svg>
+    </button>
+  );
+}
+
 export default function AccountsTable({
   initial,
   initialHasMore,
   initialTotal,
   prefixPattern,
 }: Props) {
+  const [sortKey, setSortKey] = useState<SortKey>("username");
   const [sortDir, setSortDir] = useState<SortDir>("desc");
   const [editingKey, setEditingKey] = useState<string | null>(null);
   const [, startTransition] = useTransition();
@@ -93,6 +128,15 @@ export default function AccountsTable({
   const [total, setTotal] = useState<number>(initialTotal);
   const sentinelRef = useRef<HTMLDivElement | null>(null);
 
+  // `searchInput` is what the user is typing; `appliedQuery` is what
+  // the server actually filtered on. Decoupled so typing doesn't fire a
+  // request per keystroke — only on Enter / Find / Clear. `appliedQuery`
+  // flows into refresh / changeSort / loadMore so sort + infinite-scroll
+  // respect the active search.
+  const [searchInput, setSearchInput] = useState("");
+  const [appliedQuery, setAppliedQuery] = useState("");
+  const [searching, setSearching] = useState(false);
+
   const [optimistic, applyOptimistic] = useOptimistic<Acc[], OptimisticPatch>(
     rows,
     (state, patch) =>
@@ -124,21 +168,52 @@ export default function AccountsTable({
   // the function (instead of inlining at the call site) means a future
   // 'pull to refresh' gesture has a single hook.
   async function refresh() {
-    const page = await refreshAccounts({ prefix: prefixPattern, dir: sortDir });
+    const page = await refreshAccounts({
+      prefix: prefixPattern,
+      sort: sortKey,
+      dir: sortDir,
+      q: appliedQuery,
+    });
     setRows(page.rows);
     setHasMore(page.hasMore);
     setTotal(page.total);
   }
 
-  async function changeSort(next: SortDir) {
-    if (next === sortDir) return;
-    setSortDir(next);
+  async function applySearch(nextQuery: string) {
+    setSearching(true);
+    setAppliedQuery(nextQuery);
+    try {
+      const page = await refreshAccounts({
+        prefix: prefixPattern,
+        sort: sortKey,
+        dir: sortDir,
+        q: nextQuery,
+      });
+      setRows(page.rows);
+      setHasMore(page.hasMore);
+      setTotal(page.total);
+    } finally {
+      setSearching(false);
+    }
+  }
+
+  async function changeSort(nextKey: SortKey) {
+    let nextDir: SortDir;
+    if (nextKey === sortKey) {
+      nextDir = sortDir === "asc" ? "desc" : "asc";
+    } else {
+      nextDir = "desc";
+    }
+    setSortKey(nextKey);
+    setSortDir(nextDir);
     setLoadingMore(true);
     try {
       const page = await loadMoreAccounts({
         offset: 0,
         prefix: prefixPattern,
-        dir: next,
+        sort: nextKey,
+        dir: nextDir,
+        q: appliedQuery,
       });
       setRows(page.rows);
       setHasMore(page.hasMore);
@@ -163,7 +238,9 @@ export default function AccountsTable({
         loadMoreAccounts({
           offset: rows.length,
           prefix: prefixPattern,
+          sort: sortKey,
           dir: sortDir,
+          q: appliedQuery,
         })
           .then((page) => {
             setRows((prev) => [...prev, ...page.rows]);
@@ -177,7 +254,29 @@ export default function AccountsTable({
     );
     observer.observe(sentinel);
     return () => observer.disconnect();
-  }, [hasMore, loadingMore, rows.length, prefixPattern, sortDir]);
+  }, [hasMore, loadingMore, rows.length, prefixPattern, sortKey, sortDir, appliedQuery]);
+
+  async function handleCopy(row: Acc) {
+    // Build the message line-by-line so an empty `link` (which the
+    // monitor sometimes leaves blank for new accounts) drops out
+    // entirely instead of producing a dangling "Link:" with nothing
+    // after it.
+    const lines = [
+      `Username: ${row.username}`,
+      `Password: ${row.password}`,
+    ];
+    if (row.link) lines.push(`Link: ${row.link}`);
+    const text = lines.join("\n");
+    const ok = await copyToClipboard(text);
+    setToast(
+      ok
+        ? { type: "success", message: `Copied credentials for ${row.username}` }
+        : {
+            type: "error",
+            message: `Could not copy — clipboard access blocked. Select text manually.`,
+          },
+    );
+  }
 
   async function confirmDelete() {
     if (!deleteTarget) return;
@@ -196,7 +295,32 @@ export default function AccountsTable({
     }
   }
 
-  if (rows.length === 0) {
+  const onSearchSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    void applySearch(searchInput.trim());
+  };
+  const onSearchClear = () => {
+    setSearchInput("");
+    void applySearch("");
+  };
+
+  function HeaderTh({ k, label }: { k: SortKey; label: string }) {
+    const active = sortKey === k;
+    return (
+      <button
+        type="button"
+        onClick={() => changeSort(k)}
+        className={`inline-flex items-center gap-1 text-[11px] font-medium uppercase tracking-wider transition-colors ${
+          active ? "text-zinc-900" : "text-zinc-500 hover:text-zinc-900"
+        }`}
+      >
+        {label}
+        <span aria-hidden="true">{active && sortDir === "asc" ? "↑" : "↓"}</span>
+      </button>
+    );
+  }
+
+  if (rows.length === 0 && !appliedQuery) {
     return (
       <div>
         <PageHead
@@ -204,6 +328,14 @@ export default function AccountsTable({
           loaded={0}
           onAdd={() => setCreateOpen(true)}
         />
+        <SearchBar
+          value={searchInput}
+          onChange={setSearchInput}
+          onSubmit={onSearchSubmit}
+          onClear={onSearchClear}
+          appliedQuery={appliedQuery}
+          searching={searching}
+        />
         <div className="mt-6 rounded-2xl bg-white px-8 py-16 text-center ring-1 ring-zinc-200/60">
           <p className="text-sm text-zinc-500">
             No accounts yet. Click <span className="font-medium text-zinc-700">Add</span> above to create one manually, or wait for the monitor.
@@ -231,26 +363,47 @@ export default function AccountsTable({
         loaded={optimistic.length}
         onAdd={() => setCreateOpen(true)}
       />
+      <SearchBar
+        value={searchInput}
+        onChange={setSearchInput}
+        onSubmit={onSearchSubmit}
+        onClear={onSearchClear}
+        appliedQuery={appliedQuery}
+        searching={searching}
+      />
+      {rows.length === 0 && appliedQuery && (
+        <div className="mt-6 rounded-2xl bg-white px-8 py-16 text-center ring-1 ring-zinc-200/60">
+          <p className="text-sm text-zinc-500">
+            No accounts match <span className="font-medium text-zinc-700">{appliedQuery}</span>.
+            {" "}
+            <button
+              type="button"
+              onClick={onSearchClear}
+              className="font-medium text-zinc-700 underline-offset-2 hover:underline"
+            >
+              Clear search
+            </button>
+            .
+          </p>
+        </div>
+      )}
 
+      {rows.length > 0 && (
+      <>
       {/* Desktop / tablet table */}
       <div className="mt-6 hidden overflow-hidden rounded-2xl bg-white ring-1 ring-zinc-200/60 sm:block">
         <table className="w-full table-fixed border-collapse">
           <thead>
             <tr className="bg-zinc-50/60">
               <th className="w-[18%] px-5 py-3 text-left">
-                <button
-                  type="button"
-                  onClick={() => changeSort(sortDir === "asc" ? "desc" : "asc")}
-                  className="inline-flex items-center gap-1 text-[11px] font-medium uppercase tracking-wider text-zinc-500 transition-colors hover:text-zinc-900"
-                >
-                  Username
-                  <span aria-hidden="true">{sortDir === "asc" ? "↑" : "↓"}</span>
-                </button>
+                <HeaderTh k="username" label="Username" />
               </th>
               <Th>Password</Th>
-              <Th className="w-[16%]">Status</Th>
+              <th className="w-[16%] px-5 py-3 text-left">
+                <HeaderTh k="status" label="Status" />
+              </th>
               <Th>Link</Th>
-              <th className="w-12 px-3 py-3" aria-hidden="true" />
+              <th className="w-20 px-3 py-3" aria-hidden="true" />
             </tr>
           </thead>
           <tbody className="divide-y divide-zinc-100">
@@ -293,13 +446,19 @@ export default function AccountsTable({
                     />
                   </td>
                   <td className="px-3 py-3 text-right align-middle">
-                    <DeleteButton
-                      label={row.username}
-                      onClick={() => {
-                        setDeleteError(null);
-                        setDeleteTarget(row.username);
-                      }}
-                    />
+                    <div className="inline-flex items-center gap-1">
+                      <CopyButton
+                        label={row.username}
+                        onClick={() => handleCopy(row)}
+                      />
+                      <DeleteButton
+                        label={row.username}
+                        onClick={() => {
+                          setDeleteError(null);
+                          setDeleteTarget(row.username);
+                        }}
+                      />
+                    </div>
                   </td>
                 </tr>
               );
@@ -331,13 +490,19 @@ export default function AccountsTable({
                     />
                   </div>
                 </div>
-                <DeleteButton
-                  label={row.username}
-                  onClick={() => {
-                    setDeleteError(null);
-                    setDeleteTarget(row.username);
-                  }}
-                />
+                <div className="flex items-center gap-1">
+                  <CopyButton
+                    label={row.username}
+                    onClick={() => handleCopy(row)}
+                  />
+                  <DeleteButton
+                    label={row.username}
+                    onClick={() => {
+                      setDeleteError(null);
+                      setDeleteTarget(row.username);
+                    }}
+                  />
+                </div>
               </div>
               <dl className="mt-4 space-y-3 border-t border-zinc-100 pt-4">
                 <CardRow label="Password">
@@ -380,6 +545,8 @@ export default function AccountsTable({
           End of list — {rows.length} accounts loaded
         </p>
       )}
+      </>
+      )}
 
       <CreateAccountDialog
         open={createOpen}
@@ -424,6 +591,60 @@ export default function AccountsTable({
   );
 }
 
+function SearchBar({
+  value,
+  onChange,
+  onSubmit,
+  onClear,
+  appliedQuery,
+  searching,
+}: {
+  value: string;
+  onChange: (v: string) => void;
+  onSubmit: (e: React.FormEvent) => void;
+  onClear: () => void;
+  appliedQuery: string;
+  searching: boolean;
+}) {
+  return (
+    <form onSubmit={onSubmit} role="search" className="mt-4 flex flex-wrap items-center gap-2">
+      <label className="sr-only" htmlFor="accounts-search">Search by username</label>
+      <input
+        id="accounts-search"
+        type="search"
+        autoComplete="off"
+        spellCheck={false}
+        placeholder="Search username (e.g. 13c4511)"
+        value={value}
+        onChange={(e) => onChange(e.target.value)}
+        className="min-w-0 flex-1 rounded-full bg-white px-4 py-1.5 text-sm text-zinc-900 ring-1 ring-zinc-200/60 placeholder:text-zinc-400 focus:outline-none focus:ring-2 focus:ring-zinc-900"
+      />
+      <button
+        type="submit"
+        disabled={searching}
+        className="inline-flex items-center rounded-full bg-zinc-900 px-3 py-1.5 text-xs font-medium text-white shadow-sm transition-colors hover:bg-zinc-700 disabled:cursor-not-allowed disabled:opacity-50"
+      >
+        {searching ? "Finding…" : "Find"}
+      </button>
+      {appliedQuery && (
+        <button
+          type="button"
+          onClick={onClear}
+          disabled={searching}
+          className="inline-flex items-center rounded-full bg-white px-3 py-1.5 text-xs font-medium text-zinc-700 ring-1 ring-zinc-200/60 transition-colors hover:bg-zinc-50 disabled:cursor-not-allowed disabled:opacity-50"
+        >
+          Clear
+        </button>
+      )}
+      {appliedQuery && (
+        <span className="text-[11px] text-zinc-500">
+          Filtered by <span className="font-mono text-zinc-700">{appliedQuery}</span>
+        </span>
+      )}
+    </form>
+  );
+}
+
 function Th({ children, className = "" }: { children: React.ReactNode; className?: string }) {
   return (
     <th
diff --git a/web/components/users-table.tsx b/web/components/users-table.tsx
index 2d561d5..72f2c9c 100644
--- a/web/components/users-table.tsx
+++ b/web/components/users-table.tsx
@@ -12,6 +12,7 @@ import EditableCell from "./editable-cell";
 import ConfirmDialog from "./confirm-dialog";
 import CreateUserDialog from "./create-user-dialog";
 import Toast, { type ToastMessage } from "./toast";
+import { copyToClipboard } from "@/lib/clipboard";
 
 type Props = {
   initial: User[];
@@ -20,7 +21,7 @@ type Props = {
   prefixPattern: string;
 };
 type SortDir = "asc" | "desc";
-type SortKey = "f_username" | "last_update_time";
+type SortKey = "f_username" | "t_username" | "last_update_time";
 type OptimisticPatch = {
   f_username: string;
   field: keyof Pick<User, "f_password" | "t_username" | "t_password">;
@@ -60,6 +61,38 @@ function DeleteButton({
   );
 }
 
+function CopyButton({
+  label,
+  onClick,
+}: {
+  label: string;
+  onClick: () => void;
+}) {
+  return (
+    <button
+      type="button"
+      onClick={onClick}
+      aria-label={`Copy credentials for ${label}`}
+      title="Copy from/to credentials"
+      className="inline-flex h-7 w-7 items-center justify-center rounded-md text-zinc-400 transition-colors hover:bg-zinc-100 hover:text-zinc-700 focus:outline-none focus-visible:ring-2 focus-visible:ring-zinc-400"
+    >
+      <svg
+        aria-hidden="true"
+        viewBox="0 0 16 16"
+        fill="none"
+        stroke="currentColor"
+        strokeWidth="1.5"
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        className="h-4 w-4"
+      >
+        <rect x="5.5" y="5.5" width="8" height="8" rx="1.25" />
+        <path d="M3 10.5V3.5A1 1 0 0 1 4 2.5h7" />
+      </svg>
+    </button>
+  );
+}
+
 export default function UsersTable({
   initial,
   initialHasMore,
@@ -89,6 +122,15 @@ export default function UsersTable({
   const [total, setTotal] = useState<number>(initialTotal);
   const sentinelRef = useRef<HTMLDivElement | null>(null);
 
+  // `searchInput` is what the user is typing; `appliedQuery` is what
+  // the server actually filtered on. Decoupling them means the input
+  // doesn't fire a request on every keystroke — only on Enter / Find /
+  // Clear. `appliedQuery` flows into refresh / changeSort / loadMore so
+  // sort + infinite-scroll respect the active search.
+  const [searchInput, setSearchInput] = useState("");
+  const [appliedQuery, setAppliedQuery] = useState("");
+  const [searching, setSearching] = useState(false);
+
   const [optimistic, applyOptimistic] = useOptimistic<User[], OptimisticPatch>(
     rows,
     (state, patch) =>
@@ -136,12 +178,31 @@ export default function UsersTable({
       prefix: prefixPattern,
       sort: sortKey,
       dir: sortDir,
+      q: appliedQuery,
     });
     setRows(page.rows);
     setHasMore(page.hasMore);
     setTotal(page.total);
   }
 
+  async function applySearch(nextQuery: string) {
+    setSearching(true);
+    setAppliedQuery(nextQuery);
+    try {
+      const page = await refreshUsers({
+        prefix: prefixPattern,
+        sort: sortKey,
+        dir: sortDir,
+        q: nextQuery,
+      });
+      setRows(page.rows);
+      setHasMore(page.hasMore);
+      setTotal(page.total);
+    } finally {
+      setSearching(false);
+    }
+  }
+
   async function changeSort(nextKey: SortKey) {
     let nextDir: SortDir;
     if (nextKey === sortKey) {
@@ -158,6 +219,7 @@ export default function UsersTable({
         prefix: prefixPattern,
         sort: nextKey,
         dir: nextDir,
+        q: appliedQuery,
       });
       setRows(page.rows);
       setHasMore(page.hasMore);
@@ -180,6 +242,7 @@ export default function UsersTable({
           prefix: prefixPattern,
           sort: sortKey,
           dir: sortDir,
+          q: appliedQuery,
         })
           .then((page) => {
             setRows((prev) => [...prev, ...page.rows]);
@@ -193,7 +256,24 @@ export default function UsersTable({
     );
     observer.observe(sentinel);
     return () => observer.disconnect();
-  }, [hasMore, loadingMore, rows.length, prefixPattern, sortKey, sortDir]);
+  }, [hasMore, loadingMore, rows.length, prefixPattern, sortKey, sortDir, appliedQuery]);
+
+  async function handleCopy(row: User) {
+    const text =
+      `From Username: ${row.f_username}\n` +
+      `From Password: ${row.f_password}\n` +
+      `To Username: ${row.t_username}\n` +
+      `To Password: ${row.t_password}`;
+    const ok = await copyToClipboard(text);
+    setToast(
+      ok
+        ? { type: "success", message: `Copied credentials for ${row.f_username}` }
+        : {
+            type: "error",
+            message: `Could not copy — clipboard access blocked. Select text manually.`,
+          },
+    );
+  }
 
   async function confirmDelete() {
     if (!deleteTarget) return;
@@ -223,12 +303,21 @@ export default function UsersTable({
         }`}
       >
         {label}
-        <span aria-hidden="true">{active ? (sortDir === "asc" ? "↑" : "↓") : "↕"}</span>
+        <span aria-hidden="true">{active && sortDir === "asc" ? "↑" : "↓"}</span>
       </button>
     );
   }
 
-  if (rows.length === 0) {
+  const onSearchSubmit = (e: React.FormEvent) => {
+    e.preventDefault();
+    void applySearch(searchInput.trim());
+  };
+  const onSearchClear = () => {
+    setSearchInput("");
+    void applySearch("");
+  };
+
+  if (rows.length === 0 && !appliedQuery) {
     return (
       <div>
         <PageHead
@@ -236,6 +325,14 @@ export default function UsersTable({
           loaded={0}
           onAdd={() => setCreateOpen(true)}
         />
+        <SearchBar
+          value={searchInput}
+          onChange={setSearchInput}
+          onSubmit={onSearchSubmit}
+          onClear={onSearchClear}
+          appliedQuery={appliedQuery}
+          searching={searching}
+        />
         <div className="mt-6 rounded-2xl bg-white px-8 py-16 text-center ring-1 ring-zinc-200/60">
           <p className="text-sm text-zinc-500">
             No users yet. Click <span className="font-medium text-zinc-700">Add</span> to create one manually.
@@ -261,7 +358,33 @@ export default function UsersTable({
         loaded={optimistic.length}
         onAdd={() => setCreateOpen(true)}
       />
+      <SearchBar
+        value={searchInput}
+        onChange={setSearchInput}
+        onSubmit={onSearchSubmit}
+        onClear={onSearchClear}
+        appliedQuery={appliedQuery}
+        searching={searching}
+      />
+      {rows.length === 0 && appliedQuery && (
+        <div className="mt-6 rounded-2xl bg-white px-8 py-16 text-center ring-1 ring-zinc-200/60">
+          <p className="text-sm text-zinc-500">
+            No users match <span className="font-medium text-zinc-700">{appliedQuery}</span>.
+            {" "}
+            <button
+              type="button"
+              onClick={onSearchClear}
+              className="font-medium text-zinc-700 underline-offset-2 hover:underline"
+            >
+              Clear search
+            </button>
+            .
+          </p>
+        </div>
+      )}
 
+      {rows.length > 0 && (
+      <>
       <div className="mt-6 hidden overflow-hidden rounded-2xl bg-white ring-1 ring-zinc-200/60 sm:block">
         <table className="w-full table-fixed border-collapse">
           <thead>
@@ -272,8 +395,8 @@ export default function UsersTable({
               <th className="w-[18%] px-5 py-3 text-left text-[11px] font-medium uppercase tracking-wider text-zinc-500">
                 From password
               </th>
-              <th className="w-[18%] px-5 py-3 text-left text-[11px] font-medium uppercase tracking-wider text-zinc-500">
-                To username
+              <th className="w-[18%] px-5 py-3 text-left">
+                <HeaderTh k="t_username" label="To username" />
               </th>
               <th className="w-[18%] px-5 py-3 text-left text-[11px] font-medium uppercase tracking-wider text-zinc-500">
                 To password
@@ -281,7 +404,7 @@ export default function UsersTable({
               <th className="px-5 py-3 text-left">
                 <HeaderTh k="last_update_time" label="Last update" />
               </th>
-              <th className="w-12 px-3 py-3" aria-hidden="true" />
+              <th className="w-20 px-3 py-3" aria-hidden="true" />
             </tr>
           </thead>
           <tbody className="divide-y divide-zinc-100">
@@ -326,13 +449,19 @@ export default function UsersTable({
                     {formatTime(row.last_update_time)}
                   </td>
                   <td className="px-3 py-3 text-right align-middle">
-                    <DeleteButton
-                      label={row.f_username}
-                      onClick={() => {
-                        setDeleteError(null);
-                        setDeleteTarget(row.f_username);
-                      }}
-                    />
+                    <div className="inline-flex items-center gap-1">
+                      <CopyButton
+                        label={row.f_username}
+                        onClick={() => handleCopy(row)}
+                      />
+                      <DeleteButton
+                        label={row.f_username}
+                        onClick={() => {
+                          setDeleteError(null);
+                          setDeleteTarget(row.f_username);
+                        }}
+                      />
+                    </div>
                   </td>
                 </tr>
               );
@@ -354,6 +483,10 @@ export default function UsersTable({
                   <span className="text-[11px] text-zinc-500">
                     {formatTime(row.last_update_time)}
                   </span>
+                  <CopyButton
+                    label={row.f_username}
+                    onClick={() => handleCopy(row)}
+                  />
                   <DeleteButton
                     label={row.f_username}
                     onClick={() => {
@@ -411,6 +544,8 @@ export default function UsersTable({
           End of list — {rows.length} users loaded
         </p>
       )}
+      </>
+      )}
 
       <CreateUserDialog
         open={createOpen}
@@ -455,6 +590,60 @@ export default function UsersTable({
   );
 }
 
+function SearchBar({
+  value,
+  onChange,
+  onSubmit,
+  onClear,
+  appliedQuery,
+  searching,
+}: {
+  value: string;
+  onChange: (v: string) => void;
+  onSubmit: (e: React.FormEvent) => void;
+  onClear: () => void;
+  appliedQuery: string;
+  searching: boolean;
+}) {
+  return (
+    <form onSubmit={onSubmit} role="search" className="mt-4 flex flex-wrap items-center gap-2">
+      <label className="sr-only" htmlFor="users-search">Search by username</label>
+      <input
+        id="users-search"
+        type="search"
+        autoComplete="off"
+        spellCheck={false}
+        placeholder="Search username (e.g. 13c4511)"
+        value={value}
+        onChange={(e) => onChange(e.target.value)}
+        className="min-w-0 flex-1 rounded-full bg-white px-4 py-1.5 text-sm text-zinc-900 ring-1 ring-zinc-200/60 placeholder:text-zinc-400 focus:outline-none focus:ring-2 focus:ring-zinc-900"
+      />
+      <button
+        type="submit"
+        disabled={searching}
+        className="inline-flex items-center rounded-full bg-zinc-900 px-3 py-1.5 text-xs font-medium text-white shadow-sm transition-colors hover:bg-zinc-700 disabled:cursor-not-allowed disabled:opacity-50"
+      >
+        {searching ? "Finding…" : "Find"}
+      </button>
+      {appliedQuery && (
+        <button
+          type="button"
+          onClick={onClear}
+          disabled={searching}
+          className="inline-flex items-center rounded-full bg-white px-3 py-1.5 text-xs font-medium text-zinc-700 ring-1 ring-zinc-200/60 transition-colors hover:bg-zinc-50 disabled:cursor-not-allowed disabled:opacity-50"
+        >
+          Clear
+        </button>
+      )}
+      {appliedQuery && (
+        <span className="text-[11px] text-zinc-500">
+          Filtered by <span className="font-mono text-zinc-700">{appliedQuery}</span>
+        </span>
+      )}
+    </form>
+  );
+}
+
 function MobileRow({ label, children }: { label: string; children: React.ReactNode }) {
   return (
     <div className="grid grid-cols-[max-content_1fr] items-baseline gap-x-4">
diff --git a/web/lib/api.ts b/web/lib/api.ts
index e107fd0..dcf7d5e 100644
--- a/web/lib/api.ts
+++ b/web/lib/api.ts
@@ -20,14 +20,17 @@ export type Page<T> = { rows: T[]; hasMore: boolean; total: number };
 export type AccountsPageOpts = {
   offset?: number;
   prefix?: string;
+  sort?: "username" | "status";
   dir?: "asc" | "desc";
+  q?: string;
 };
 
 export type UsersPageOpts = {
   offset?: number;
   prefix?: string;
-  sort?: "f_username" | "last_update_time";
+  sort?: "f_username" | "t_username" | "last_update_time";
   dir?: "asc" | "desc";
+  q?: string;
 };
 
 type FetchInit = {
@@ -57,18 +60,7 @@ export async function fetchApi(path: string, options: FetchInit = {}): Promise<u
 }
 
 function buildAccountsUrl(opts: AccountsPageOpts): string {
-  const { offset = 0, prefix = "", dir = "desc" } = opts;
-  const params = new URLSearchParams({
-    limit: String(PAGE_SIZE),
-    offset: String(offset),
-    dir,
-  });
-  if (prefix) params.set("prefix", prefix);
-  return `/acc/?${params.toString()}`;
-}
-
-function buildUsersUrl(opts: UsersPageOpts): string {
-  const { offset = 0, prefix = "", sort = "last_update_time", dir = "desc" } = opts;
+  const { offset = 0, prefix = "", sort = "username", dir = "desc", q = "" } = opts;
   const params = new URLSearchParams({
     limit: String(PAGE_SIZE),
     offset: String(offset),
@@ -76,6 +68,20 @@ function buildUsersUrl(opts: UsersPageOpts): string {
     dir,
   });
   if (prefix) params.set("prefix", prefix);
+  if (q) params.set("q", q);
+  return `/acc/?${params.toString()}`;
+}
+
+function buildUsersUrl(opts: UsersPageOpts): string {
+  const { offset = 0, prefix = "", sort = "last_update_time", dir = "desc", q = "" } = opts;
+  const params = new URLSearchParams({
+    limit: String(PAGE_SIZE),
+    offset: String(offset),
+    sort,
+    dir,
+  });
+  if (prefix) params.set("prefix", prefix);
+  if (q) params.set("q", q);
   return `/user/?${params.toString()}`;
 }
 
diff --git a/web/lib/clipboard.ts b/web/lib/clipboard.ts
new file mode 100644
index 0000000..5e0e19c
--- /dev/null
+++ b/web/lib/clipboard.ts
@@ -0,0 +1,46 @@
+/**
+ * Copy `text` to the system clipboard.
+ *
+ * The modern `navigator.clipboard.writeText()` only works in secure
+ * contexts (HTTPS / localhost / file://). This deployment runs over
+ * plain HTTP on the internal network, where that API is gated, so we
+ * fall back to the legacy `textarea + execCommand("copy")` pattern.
+ * `execCommand` is deprecated but every shipping browser still
+ * implements it for the copy command, and it works in non-secure
+ * contexts where the modern API doesn't.
+ *
+ * Returns true on success, false if both paths fail.
+ */
+export async function copyToClipboard(text: string): Promise<boolean> {
+  if (typeof navigator !== "undefined" && navigator.clipboard?.writeText) {
+    try {
+      await navigator.clipboard.writeText(text);
+      return true;
+    } catch {
+      // Fall through to legacy path — secure-context block, permission
+      // denial, or any other modern-API failure.
+    }
+  }
+
+  if (typeof document === "undefined") return false;
+  const ta = document.createElement("textarea");
+  ta.value = text;
+  ta.setAttribute("readonly", "");
+  // Position offscreen but still focusable; some browsers refuse to
+  // copy from elements that are display:none or visibility:hidden.
+  ta.style.position = "fixed";
+  ta.style.top = "0";
+  ta.style.left = "0";
+  ta.style.opacity = "0";
+  ta.style.pointerEvents = "none";
+  document.body.appendChild(ta);
+  try {
+    ta.focus();
+    ta.select();
+    return document.execCommand("copy");
+  } catch {
+    return false;
+  } finally {
+    document.body.removeChild(ta);
+  }
+}