Move band management into dedicated settings pages

- Add BandSettingsPage (/bands/:id/settings/:panel) with Members,
  Storage, and Band Settings panels matching the mockup design
- Strip members list, invite controls, and NC folder config from
  BandPage — library view now focuses purely on recordings workflow
- Add band-scoped nav section to AppShell sidebar (Members, Storage,
  Band Settings) with correct per-panel active states
- Fix amAdmin bug: was checking if any member is admin; now correctly
  checks if the current user holds the admin role
- Add 31 vitest tests covering BandPage cleanliness, routing, access
  control (admin vs member), and per-panel mutation behaviour
- Add test:web, test:api:unit, test:feature (post-feature pipeline),
  and ci tasks to Taskfile; frontend tests run via podman node:20-alpine
- Add README with architecture overview, setup guide, and test docs
- Add @testing-library/dom and @testing-library/jest-dom to package.json

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/package.json

@@ -23,6 +23,8 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.39.4",
+    "@testing-library/dom": "^10.4.1",
+    "@testing-library/jest-dom": "^6.9.1",
     "@testing-library/react": "^16.0.1",
     "@testing-library/user-event": "^14.5.2",
     "@types/react": "^18.3.5",