task-11: complete QA + hardening with resilience fixes

- Created comprehensive QA checklist covering edge cases (missing EXIF, timezones, codecs, corrupt files)
- Added ErrorBoundary component wrapped around TimelineTree and MediaPanel
- Created global error.tsx page for unhandled errors
- Improved failed asset UX with red borders, warning icons, and inline error display
- Added loading skeletons to TimelineTree and MediaPanel
- Added retry button for failed media loads
- Created DEPLOYMENT_VALIDATION.md with validation commands and checklist
- Applied k8s recommendations:
  - Changed node affinity to required for compute nodes (Pi 5)
  - Enabled Tailscale LoadBalancer service for MinIO S3 (reliable Range requests)
  - Enabled cleanup CronJob for staging files

apps/web/app/page.tsx

@@ -4,6 +4,7 @@ import Link from "next/link";
 import { getAppName } from "@tline/config";
 import { useState } from "react";
 
+import { ErrorBoundary } from "./components/ErrorBoundary";
 import { MediaPanel } from "./components/MediaPanel";
 import { TimelineTree } from "./components/TimelineTree";
 
@@ -32,8 +33,12 @@ export default function HomePage() {
           alignItems: "start",
         }}
       >
-        <TimelineTree onSelectDay={setSelectedDayIso} />
-        <MediaPanel selectedDayIso={selectedDayIso} />
+        <ErrorBoundary>
+          <TimelineTree onSelectDay={setSelectedDayIso} />
+        </ErrorBoundary>
+        <ErrorBoundary>
+          <MediaPanel selectedDayIso={selectedDayIso} />
+        </ErrorBoundary>
       </div>
     </main>
   );