diff --git a/apps/web/src/app/activity/page.tsx b/apps/web/src/app/activity/page.tsx
index 01572c8..db18c37 100644
--- a/apps/web/src/app/activity/page.tsx
+++ b/apps/web/src/app/activity/page.tsx
@@ -215,17 +215,26 @@ export default async function ActivityPage({ searchParams }: PageProps) {
         )}
       </div>
 
+      {/* Six tabs (All / Success / Partial / Failed / Skipped / Archived)
+          packed into a phone-width row left every label squeezed to
+          ~50px. Wrap the list in an overflow-x scroller so each tab
+          keeps a readable label + comfortable touch target on mobile;
+          on desktop the row fits naturally and no scroll bar appears.
+          Negative margins extend the scroller to the page edges so the
+          first/last tabs don't look clipped against the container. */}
       <Tabs value={filter}>
-        <TabsList className="w-full">
-          {FILTER_TABS.map(({ value, label }) => (
-            <TabsTrigger key={value} value={value} asChild>
-              {/* eslint-disable-next-line @typescript-eslint/no-explicit-any */}
-              <Link href={(value === "all" ? "/activity" : `/activity?filter=${value}`) as any}>
-                {label}
-              </Link>
-            </TabsTrigger>
-          ))}
-        </TabsList>
+        <div className="-mx-4 overflow-x-auto px-4 sm:mx-0 sm:px-0 [scrollbar-width:none] [&::-webkit-scrollbar]:hidden">
+          <TabsList>
+            {FILTER_TABS.map(({ value, label }) => (
+              <TabsTrigger key={value} value={value} asChild>
+                {/* eslint-disable-next-line @typescript-eslint/no-explicit-any */}
+                <Link href={(value === "all" ? "/activity" : `/activity?filter=${value}`) as any}>
+                  {label}
+                </Link>
+              </TabsTrigger>
+            ))}
+          </TabsList>
+        </div>
       </Tabs>
 
       {filtered.length > 0 ? (
diff --git a/apps/web/src/components/app-shell.tsx b/apps/web/src/components/app-shell.tsx
index bd1c50d..945b410 100644
--- a/apps/web/src/components/app-shell.tsx
+++ b/apps/web/src/components/app-shell.tsx
@@ -131,8 +131,12 @@ function Sidebar() {
 
   return (
     <aside className="hidden sm:flex fixed left-0 top-0 bottom-0 z-40 w-56 flex-col border-r border-border bg-sidebar">
-      {/* Bot name / brand */}
-      <div className="flex h-14 items-center gap-2 px-4 border-b border-sidebar-border shrink-0">
+      {/* Bot name / brand — clickable, returns to the dashboard. */}
+      <Link
+        href="/"
+        aria-label="Go to dashboard"
+        className="flex h-14 items-center gap-2 px-4 border-b border-sidebar-border shrink-0 hover:bg-sidebar-accent/40 transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring focus-visible:ring-inset"
+      >
         <span
           aria-hidden
           className="flex size-6 items-center justify-center rounded-md bg-primary text-[10px] font-bold uppercase text-primary-foreground"
@@ -142,7 +146,7 @@ function Sidebar() {
         <span className="text-sm font-semibold tracking-tight text-sidebar-foreground">
           WhatsApp Bot
         </span>
-      </div>
+      </Link>
 
       {/* Nav items */}
       <nav aria-label="Primary navigation" className="flex flex-col gap-1 p-3 flex-1">
diff --git a/apps/web/src/lib/whatsapp-media.test.ts b/apps/web/src/lib/whatsapp-media.test.ts
index 40cda6d..ade4616 100644
--- a/apps/web/src/lib/whatsapp-media.test.ts
+++ b/apps/web/src/lib/whatsapp-media.test.ts
@@ -2,6 +2,7 @@ import { describe, it, expect } from "vitest";
 import {
   classifyMediaKind,
   formatBytes,
+  isUnsupportedImageMime,
   validateForWhatsApp,
   WA_LIMITS,
   WA_MAX_BYTES,
@@ -99,6 +100,37 @@ describe("validateForWhatsApp — per-kind WA caps", () => {
   });
 });
 
+describe("isUnsupportedImageMime / HEIC/HEIF/AVIF guard", () => {
+  it("recognises HEIC, HEIF, AVIF (case-insensitive)", () => {
+    expect(isUnsupportedImageMime("image/heic")).toBe(true);
+    expect(isUnsupportedImageMime("image/heif")).toBe(true);
+    expect(isUnsupportedImageMime("IMAGE/HEIC")).toBe(true);
+    expect(isUnsupportedImageMime("image/heic-sequence")).toBe(true);
+    expect(isUnsupportedImageMime("image/avif")).toBe(true);
+  });
+
+  it("does not flag normal image formats", () => {
+    expect(isUnsupportedImageMime("image/jpeg")).toBe(false);
+    expect(isUnsupportedImageMime("image/png")).toBe(false);
+    expect(isUnsupportedImageMime("image/webp")).toBe(false);
+    expect(isUnsupportedImageMime("image/gif")).toBe(false);
+  });
+
+  it("validateForWhatsApp rejects a HEIC upload with a clear hint", () => {
+    const r = validateForWhatsApp("image/heic", 2 * MB);
+    expect(r.ok).toBe(false);
+    if (!r.ok) {
+      expect(r.kind).toBe("image");
+      expect(r.error).toBe("Images are not supported, please re-upload images");
+    }
+  });
+
+  it("validateForWhatsApp rejects HEIC even when below the 5 MB image cap", () => {
+    const r = validateForWhatsApp("image/heif", 100 * 1024); // 100 KB
+    expect(r.ok).toBe(false);
+  });
+});
+
 describe("WA_MAX_BYTES is the largest single-kind cap", () => {
   it("equals the document cap (100 MB)", () => {
     expect(WA_MAX_BYTES).toBe(WA_LIMITS.document);
diff --git a/apps/web/src/lib/whatsapp-media.ts b/apps/web/src/lib/whatsapp-media.ts
index 111001a..c87f406 100644
--- a/apps/web/src/lib/whatsapp-media.ts
+++ b/apps/web/src/lib/whatsapp-media.ts
@@ -47,6 +47,26 @@ export function classifyMediaKind(mimeType: string): WaMediaKind {
   return "document";
 }
 
+/**
+ * MIME types that look like images to the classifier but break the
+ * Baileys send path because the bot's bundled Sharp doesn't have the
+ * relevant decoder (HEIF/HEIC, AVIF). The image otherwise uploads
+ * silently with no thumbnail and a logged warning, which reads to
+ * users as "image send broken". Rejecting at the upload boundary
+ * with a useful message is friendlier than the half-success.
+ */
+const UNSUPPORTED_IMAGE_MIMES: ReadonlySet<string> = new Set([
+  "image/heic",
+  "image/heif",
+  "image/heic-sequence",
+  "image/heif-sequence",
+  "image/avif",
+]);
+
+export function isUnsupportedImageMime(mimeType: string): boolean {
+  return UNSUPPORTED_IMAGE_MIMES.has(mimeType.toLowerCase());
+}
+
 export type WaSizeCheck =
   | { ok: true; kind: WaMediaKind; limitBytes: number }
   | { ok: false; kind: WaMediaKind; limitBytes: number; error: string };
@@ -67,6 +87,17 @@ export function validateForWhatsApp(
   if (sizeBytes <= 0) {
     return { ok: false, kind, limitBytes, error: "Empty file" };
   }
+  if (kind === "image" && isUnsupportedImageMime(mimeType)) {
+    // The bot's Sharp binary doesn't ship a HEIF/AVIF decoder, so the
+    // thumbnail-extraction step throws and Baileys sends the message
+    // without a preview. Block at the door with a clear message.
+    return {
+      ok: false,
+      kind,
+      limitBytes,
+      error: "Images are not supported, please re-upload images",
+    };
+  }
   if (sizeBytes > limitBytes) {
     return {
       ok: false,