feat(mosaic): merge @mosaic/cli into @mosaic/mosaic

@mosaic/mosaic is now the single package providing both:
- 'mosaic' binary (CLI: yolo, coord, prdy, tui, gateway, etc.)
- 'mosaic-wizard' binary (installation wizard)

Changes:
- Move packages/cli/src/* into packages/mosaic/src/
- Convert dynamic @mosaic/mosaic imports to static relative imports
- Add CLI deps (ink, react, socket.io-client, @mosaic/config) to mosaic
- Add jsx: react-jsx to mosaic's tsconfig
- Exclude packages/cli from workspace (pnpm-workspace.yaml)
- Update install.sh to install @mosaic/mosaic instead of @mosaic/cli
- Bump version to 0.0.17

This eliminates the circular dependency between @mosaic/cli and
@mosaic/mosaic that was blocking the build graph.

packages/mosaic/src/commands/with-auth.ts

@@ -0,0 +1,29 @@
+import type { AuthResult } from '../auth.js';
+
+export interface AuthContext {
+  gateway: string;
+  session: AuthResult;
+  cookie: string;
+}
+
+/**
+ * Load and validate the user's auth session.
+ * Exits with an error message if not signed in or session expired.
+ */
+export async function withAuth(gateway: string): Promise<AuthContext> {
+  const { loadSession, validateSession } = await import('../auth.js');
+
+  const session = loadSession(gateway);
+  if (!session) {
+    console.error('Not signed in. Run `mosaic login` first.');
+    process.exit(1);
+  }
+
+  const valid = await validateSession(gateway, session.cookie);
+  if (!valid) {
+    console.error('Session expired. Run `mosaic login` again.');
+    process.exit(1);
+  }
+
+  return { gateway, session, cookie: session.cookie };
+}