Stabilize the desktop transcript so long agent sessions stay readable

The desktop app now keeps the composer stable while turns are active,
reduces low-signal tool noise in the transcript, restores project context
under the composer after session creation, and relies on the CLI's own
permission requests instead of injecting broader desktop-side Bash asks.

This also brings in the supporting desktop app source tree and the server
routes/session metadata needed for git info, filesystem browsing, session
resume, slash commands, and SDK-backed permission bridging so the UI can
operate as a coherent feature instead of a partial patch.

Constraint: Desktop transcript needs to stay usable during long multi-tool sessions without hiding file-change diffs
Constraint: Permission prompts must mirror CLI behavior closely enough that read-only commands do not get desktop-only prompts
Rejected: Keep rendering Read/Bash bodies inline | too noisy and unlike the intended transcript model
Rejected: Commit only the touched desktop files | would leave the newly introduced desktop app incomplete in git history
Confidence: medium
Scope-risk: broad
Reversibility: messy
Directive: Treat non-writing tools as summary-first transcript events; do not re-expand them by default without validating the UX against long sessions
Tested: cd desktop && bun run lint
Tested: cd desktop && bun run test -- --run
Tested: bun test src/server/__tests__/conversations.test.ts
Not-tested: Manual visual regression against the exact screenshots in a live desktop session
Not-tested: Full root TypeScript check (repository still has unrelated extracted-native parse failures)

desktop/tsconfig.json

@@ -0,0 +1,25 @@
+{
+  "compilerOptions": {
+    "target": "ES2021",
+    "useDefineForClassFields": true,
+    "lib": ["ES2021", "DOM", "DOM.Iterable"],
+    "module": "ESNext",
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "isolatedModules": true,
+    "moduleDetection": "force",
+    "noEmit": true,
+    "jsx": "react-jsx",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "noUncheckedIndexedAccess": true,
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["src/*"]
+    }
+  },
+  "include": ["src"]
+}