fix(unpair): allow whatsapp_groups delete by relaxing run_targets FK

Symptom
-------
Click Unpair on a connected account (or Delete Account). The web
action runs:

    DELETE FROM whatsapp_groups WHERE account_id = ?

and Postgres rejects it:

    error: update or delete on table "whatsapp_groups" violates
    foreign key constraint
    "reminder_run_targets_group_id_whatsapp_groups_id_fk"
    on table "reminder_run_targets"

Cause
-----
\`reminder_run_targets.group_id\` had a non-null FK to
whatsapp_groups.id with no ON DELETE rule (defaults to NO ACTION /
RESTRICT). So any reminder that had ever fired pinned the group rows
in place. Unpair couldn't wipe the synced groups, the action threw,
and the row never reached \`status='unpaired'\`.

Fix
---
Mirror the pattern \`reminder_runs.reminder_id\` already uses
(migration 0005): nullable column + ON DELETE SET NULL + a
denormalised label snapshot, so historical fan-out records survive a
group wipe but stay readable.

Migration 0006:
- Drop the composite \`(run_id, group_id)\` PK; add a surrogate
  \`id uuid pk default gen_random_uuid()\` since \`group_id\` can no
  longer be part of the PK once it's nullable.
- Make \`group_id\` nullable.
- Re-create the FK with ON DELETE SET NULL.
- Add \`group_label text\` for the snapshot.

fire-reminder.ts now writes the group's name into \`group_label\`
on every insert path (success / failed / skipped /
account-not-connected / group-missing) so the Activity tab can keep
showing "Sent to <Group Name>" even after the group is gone.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/bot/src/scheduler/fire-reminder.ts

@@ -40,9 +40,14 @@ export async function fireReminder(payload: FireReminderPayload): Promise<void>
   if (!session) {
     logger.warn({ reminderId: reminder.id }, "fire-reminder: account not connected");
     for (const target of reminder.targets) {
+      const g = await db.query.whatsappGroups.findFirst({
+        where: (g, { eq }) => eq(g.id, target.groupId),
+        columns: { name: true },
+      });
       await db.insert(reminderRunTargets).values({
         runId,
         groupId: target.groupId,
+        groupLabel: g?.name ?? null,
         status: "skipped",
         error: "account not connected",
       });
@@ -64,6 +69,7 @@ export async function fireReminder(payload: FireReminderPayload): Promise<void>
       await db.insert(reminderRunTargets).values({
         runId,
         groupId: target.groupId,
+        groupLabel: null,
         status: "skipped",
         error: "group missing from db",
       });
@@ -104,6 +110,7 @@ export async function fireReminder(payload: FireReminderPayload): Promise<void>
       await db.insert(reminderRunTargets).values({
         runId,
         groupId: target.groupId,
+        groupLabel: group.name,
         status: "sent",
         waMessageId: lastMessageId ?? null,
         latencyMs: Date.now() - start,
@@ -114,6 +121,7 @@ export async function fireReminder(payload: FireReminderPayload): Promise<void>
       await db.insert(reminderRunTargets).values({
         runId,
         groupId: target.groupId,
+        groupLabel: group.name,
         status: "failed",
         error: (err as Error).message,
       });

packages/db/migrations/0006_adorable_nehzno.sql

@@ -0,0 +1,11 @@
+ALTER TABLE "reminder_run_targets" DROP CONSTRAINT "reminder_run_targets_group_id_whatsapp_groups_id_fk";
+--> statement-breakpoint
+ALTER TABLE "reminder_run_targets" DROP CONSTRAINT "reminder_run_targets_run_id_group_id_pk";--> statement-breakpoint
+ALTER TABLE "reminder_run_targets" ALTER COLUMN "group_id" DROP NOT NULL;--> statement-breakpoint
+ALTER TABLE "reminder_run_targets" ADD COLUMN "id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL;--> statement-breakpoint
+ALTER TABLE "reminder_run_targets" ADD COLUMN "group_label" text;--> statement-breakpoint
+DO $$ BEGIN
+ ALTER TABLE "reminder_run_targets" ADD CONSTRAINT "reminder_run_targets_group_id_whatsapp_groups_id_fk" FOREIGN KEY ("group_id") REFERENCES "public"."whatsapp_groups"("id") ON DELETE set null ON UPDATE no action;
+EXCEPTION
+ WHEN duplicate_object THEN null;
+END $$;

packages/db/migrations/meta/_journal.json

@@ -43,6 +43,13 @@
       "when": 1778347437350,
       "tag": "0005_flippant_joystick",
       "breakpoints": true
+    },
+    {
+      "idx": 6,
+      "version": "7",
+      "when": 1778385559051,
+      "tag": "0006_adorable_nehzno",
+      "breakpoints": true
     }
   ]
 }

packages/db/src/schema.ts

@@ -122,20 +122,20 @@ export const reminderRuns = pgTable("reminder_runs", {
   errorSummary: text("error_summary"),
 });
 
-export const reminderRunTargets = pgTable(
-  "reminder_run_targets",
-  {
-    runId: uuid("run_id").notNull().references(() => reminderRuns.id, { onDelete: "cascade" }),
-    groupId: uuid("group_id").notNull().references(() => whatsappGroups.id),
-    status: text("status").notNull(),
-    waMessageId: text("wa_message_id"),
-    error: text("error"),
-    latencyMs: integer("latency_ms"),
-  },
-  (t) => ({
-    pk: primaryKey({ columns: [t.runId, t.groupId] }),
-  }),
-);
+export const reminderRunTargets = pgTable("reminder_run_targets", {
+  id: uuid("id").primaryKey().defaultRandom(),
+  runId: uuid("run_id").notNull().references(() => reminderRuns.id, { onDelete: "cascade" }),
+  // Nullable + ON DELETE SET NULL: unpair/delete-account wipes the
+  // associated whatsapp_groups rows but the historical fan-out record
+  // ("we tried to send to this group, here's the result") must survive.
+  // The accompanying snapshot field below preserves the readable label.
+  groupId: uuid("group_id").references(() => whatsappGroups.id, { onDelete: "set null" }),
+  groupLabel: text("group_label"),
+  status: text("status").notNull(),
+  waMessageId: text("wa_message_id"),
+  error: text("error"),
+  latencyMs: integer("latency_ms"),
+});
 
 export const auditLog = pgTable("audit_log", {
   id: uuid("id").primaryKey().defaultRandom(),