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/src/App.tsx

@@ -6,6 +6,7 @@ import { AppShell } from "./components/AppShell";
 import { LoginPage } from "./pages/LoginPage";
 import { HomePage } from "./pages/HomePage";
 import { BandPage } from "./pages/BandPage";
+import { BandSettingsPage } from "./pages/BandSettingsPage";
 import { SessionPage } from "./pages/SessionPage";
 import { SongPage } from "./pages/SongPage";
 import { SettingsPage } from "./pages/SettingsPage";
@@ -50,6 +51,18 @@ export default function App() {
               </ShellRoute>
             }
           />
+          <Route
+            path="/bands/:bandId/settings"
+            element={<Navigate to="members" replace />}
+          />
+          <Route
+            path="/bands/:bandId/settings/:panel"
+            element={
+              <ShellRoute>
+                <BandSettingsPage />
+              </ShellRoute>
+            }
+          />
           <Route
             path="/bands/:bandId/sessions/:sessionId"
             element={