feat(app): add incremental React session path (#1362)

* feat(server): add workspace session read APIs

Expose workspace-scoped session list, detail, message, and snapshot reads so the client can fetch session data without depending on activation choreography.

* feat(app): route mounted session reads through OpenWork APIs

Use the new workspace-scoped session read endpoints for mounted OpenWork clients so the current frontend stops depending on direct session proxy reads for list, detail, message, and todo loading.

* feat(app): add React read-only session transcript

Introduce a feature-gated React island for the session transcript so we can replace the session surface incrementally while keeping the Solid shell intact.

* feat(app): add React session composer surface

Extend the feature-gated React session island to own its draft, prompt send, stop flow, and snapshot polling so the session body can evolve independently from the Solid composer.

* feat(app): add React session transition model

Keep the React session surface stable during session switches by tracking rendered vs intended session state and exposing a developer debug panel for render-source and transition inspection.

* docs(prd): add React migration plan to repo

Copy the incremental React adoption PRD into the OpenWork repo so the migration plan lives next to the implementation and PR branch.

* docs(prd): sync full React migration plan

Replace the shortened repo copy with the full incremental React adoption PRD so the implementation branch and product plan stay in sync.

* feat(desktop): add React session launch modes

Add dedicated Tauri dev and debug-build entrypoints for the React session path and honor a build-time React session flag before local storage so the alternate shell is easy to launch and reproduce.

* fix(app): fall back to legacy mounted session reads

Keep the new app working against older OpenWork servers by falling back to the original mounted OpenCode session reads when the workspace-scoped session read APIs are unavailable.

apps/desktop/package.json

@@ -6,9 +6,11 @@
   "type": "module",
   "scripts": {
     "dev": "OPENWORK_DEV_MODE=1 OPENWORK_DATA_DIR=\"$HOME/.openwork/openwork-orchestrator-dev\" tauri dev --config src-tauri/tauri.dev.conf.json --config \"{\\\"build\\\":{\\\"devUrl\\\":\\\"http://localhost:${PORT:-5173}\\\"}}\"",
+    "dev:react-session": "OPENWORK_DEV_MODE=1 VITE_OPENWORK_REACT_SESSION=1 OPENWORK_DATA_DIR=\"$HOME/.openwork/openwork-orchestrator-dev-react\" tauri dev --config src-tauri/tauri.dev.conf.json --config \"{\\\"build\\\":{\\\"devUrl\\\":\\\"http://localhost:${PORT:-5173}\\\"}}\"",
     "dev:windows": "node ./scripts/dev-windows.mjs",
     "dev:windows:x64": "node ./scripts/dev-windows.mjs x64",
     "build": "tauri build",
+    "build:debug:react-session": "VITE_OPENWORK_REACT_SESSION=1 tauri build --debug",
     "prepare:sidecar": "node ./scripts/prepare-sidecar.mjs"
   },
   "devDependencies": {