Clean frontend app entrypoint

CHANGELOG.md

@@ -7,6 +7,13 @@
 
 # Changelog
 
+## Sprint 42 App entrypoint cleanup (2026-06-17)
+
+- Removed the stale `FormEvent`/`useState` React imports from `frontend/src/App.tsx`.
+- Removed the UTF-8 BOM from the frontend entrypoint so future text patches and static checks are stable.
+- Added a regression test that keeps `App.tsx` free of the stale imports and BOM.
+- No behavior, API contracts, migrations, provider fetching or AI behavior changed.
+
 ## Sprint 41 Demo workflow hook decomposition (2026-06-17)
 
 - Moved offline demo workflow orchestration from `App.tsx` into `frontend/src/hooks/useDemoWorkflow.ts`.

backend/tests/test_sprint39_frontend_orchestration_hooks.py

@@ -27,6 +27,17 @@ def test_app_uses_shared_orchestration_hooks() -> None:
     assert "externalApi" not in app
 
 
+def test_app_entrypoint_has_clean_encoding_and_react_imports() -> None:
+    app_path = ROOT / "frontend" / "src" / "App.tsx"
+    app_bytes = app_path.read_bytes()
+    app = app_path.read_text(encoding="utf-8")
+
+    assert not app_bytes.startswith(b"\xef\xbb\xbf")
+    assert "import { useEffect, useMemo } from 'react'" in app
+    assert "FormEvent" not in app
+    assert "useState" not in app
+
+
 def test_demo_workflow_hook_owns_demo_api_and_cross_module_selection() -> None:
     hook = (ROOT / "frontend" / "src" / "hooks" / "useDemoWorkflow.ts").read_text(encoding="utf-8")
 

docs/CODEX_EXECUTION_LOG.md

@@ -1,3 +1,32 @@
+## Sprint 42 App entrypoint cleanup (2026-06-17)
+
+Changed:
+- Removed the stale `FormEvent`/`useState` React imports from `frontend/src/App.tsx`.
+- Removed the UTF-8 BOM from `App.tsx` so patches and static checks use normal UTF-8 text.
+- Added a regression test that verifies the clean entrypoint encoding and React import set.
+- Recorded the current `App.tsx` size audit: 622 lines after the orchestration hook decomposition passes.
+
+Validation:
+- `cd backend && python -m pytest tests/test_sprint39_frontend_orchestration_hooks.py -q` passed: 8 tests.
+- `python -m compileall backend/app` passed.
+- `cd backend && python -m pytest -W error::DeprecationWarning` passed: 192 tests.
+- `bash scripts/run_readiness_check.sh` passed.
+- `cd frontend && npm run typecheck` passed.
+- `cd frontend && npm run build` passed.
+- `cd backend && python -m alembic heads` passed: `202606120900 (head)`.
+- `cd backend && python -m alembic upgrade head --sql` passed.
+- `bash -n scripts/live_migration_smoke.sh` passed.
+
+Open:
+- Tower deployment and runtime smoke should run before considering this pass deployed.
+
+Limitations:
+- No UX behavior, API contracts, migrations, provider fetching or AI behavior changed.
+- `App.tsx` remains a large composition root; the remaining size is primarily panel wiring and hook outputs.
+
+Next recommended pass:
+- Optional bootstrap-effect extraction if another no-behavior size reduction is useful.
+
 ## Sprint 41 Demo workflow hook decomposition (2026-06-17)
 
 Changed:

docs/TODO.md

@@ -54,7 +54,8 @@ This file now starts with the current implementation status. Older preparation/b
 - [x] Provider, change-detection and map-workspace orchestration hook decomposition.
 - [x] Project/area/dataset cross-load orchestration hook decomposition.
 - [x] Demo workflow orchestration hook decomposition.
-- [ ] Final `App.tsx` import/encoding cleanup and size audit.
+- [x] Final `App.tsx` import/encoding cleanup and size audit.
+- [ ] Optional final bootstrap-effect extraction if `App.tsx` orchestration needs another size reduction.
 
 ## Sprint 8 status
 

frontend/src/App.tsx

@@ -1,4 +1,4 @@
-import { FormEvent, useEffect, useMemo, useState } from 'react'
+import { useEffect, useMemo } from 'react'
 import './styles/app.css'
 import { ChangeDetectionPanel } from './components/analysis/ChangeDetectionPanel'
 import { DatasetDetailPanel } from './components/datasets/DatasetDetailPanel'