Fix bugs across app + server, optimize UI/UX, add Gitea CI

Bug fixes (Flutter):
- Wrap multi-statement DB writes (insert/update/delete note, deleteDocument,
  deletePageData, OCR FTS merge, migrations) in transactions to prevent data
  loss on interruption and a read-modify-write FTS race.
- Fix PdfDocument leaks on exception (try/finally dispose) and preserve image
  aspect ratio when stamping images onto PDF pages.
- Guard file-picker against empty selection (was .single -> crash).
- Fix eraser ConcurrentModificationError and unmodifiable-list crash on PDF
  pages; capture page synchronously on save to stop wrong-page data loss.
- Fix Riverpod DB-not-ready races, broken pull-to-refresh, settings load race,
  and search N+1; transform stored annotations on PDF page rotation.
- Normalize pen pressure for devices without a pressure range.
- PPT: single source of truth for slide strokes so ink displays and exports.

UI/UX:
- Material 3 typography, theme-aware colors (dark-mode fixes), hover cursors
  and right-click/visible actions on desktop, keyboard shortcuts (undo/redo/
  save/find), toolbar overflow handling, friendlier empty states, semantic OCR
  status badges, relative timestamps, 1-based page indicators, large-deck PPT
  navigation, and a scratchpad-scope label in split view.

Server (optional backend):
- Persist JWT secret (was per-process random), block path traversal in storage,
  fix CORS '*'+credentials, add OCR job ownership checks, last-writer-wins sync
  guard, constant-time login, and split out heavy OCR deps so the API/tests run
  without them.

CI: Gitea workflows for format+analyze+test (Linux, system sqlite) and a
Windows release build; pristine `flutter analyze`, all Flutter and server tests
green.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

server/tests/test_notes.py

@@ -0,0 +1,146 @@
+"""Tests for notes CRUD and sync endpoints."""
+
+import sys, os
+sys.path.insert(0, os.path.dirname(__file__))
+
+import pytest
+import pytest_asyncio
+from httpx import AsyncClient
+from helpers import auth_header, register_and_login
+
+
+@pytest.mark.asyncio
+async def test_create_note(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    resp = await client.post(
+        "/api/notes",
+        json={
+            "id": "note-001",
+            "title": "Test Note",
+            "tags": ["tag1", "tag2"],
+            "strokes_json": "[{\"x\":1,\"y\":2}]",
+        },
+        headers=auth_header(token),
+    )
+    assert resp.status_code == 201
+    data = resp.json()
+    assert data["id"] == "note-001"
+    assert data["title"] == "Test Note"
+    assert data["tags"] == ["tag1", "tag2"]
+
+
+@pytest.mark.asyncio
+async def test_get_note(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    await client.post(
+        "/api/notes",
+        json={"id": "note-002", "title": "Fetch Me", "tags": [], "strokes_json": "[]"},
+        headers=auth_header(token),
+    )
+    resp = await client.get("/api/notes/note-002", headers=auth_header(token))
+    assert resp.status_code == 200
+    assert resp.json()["title"] == "Fetch Me"
+
+
+@pytest.mark.asyncio
+async def test_get_note_not_found(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    resp = await client.get("/api/notes/nonexistent", headers=auth_header(token))
+    assert resp.status_code == 404
+
+
+@pytest.mark.asyncio
+async def test_update_note(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    await client.post(
+        "/api/notes",
+        json={"id": "note-003", "title": "Original", "tags": [], "strokes_json": "[]"},
+        headers=auth_header(token),
+    )
+    resp = await client.post(
+        "/api/notes",
+        json={"id": "note-003", "title": "Updated", "tags": ["new"], "strokes_json": "[1]"},
+        headers=auth_header(token),
+    )
+    assert resp.status_code == 201
+    assert resp.json()["title"] == "Updated"
+    assert resp.json()["tags"] == ["new"]
+
+
+@pytest.mark.asyncio
+async def test_delete_note(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    await client.post(
+        "/api/notes",
+        json={"id": "note-004", "title": "Delete Me", "tags": [], "strokes_json": "[]"},
+        headers=auth_header(token),
+    )
+    resp = await client.delete("/api/notes/note-004", headers=auth_header(token))
+    assert resp.status_code == 200
+    resp = await client.get("/api/notes/note-004", headers=auth_header(token))
+    assert resp.status_code == 404
+
+
+@pytest.mark.asyncio
+async def test_list_notes_with_since(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    await client.post(
+        "/api/notes",
+        json={"id": "note-005", "title": "Old", "tags": [], "strokes_json": "[]"},
+        headers=auth_header(token),
+    )
+    resp = await client.get("/api/notes", headers=auth_header(token))
+    assert resp.status_code == 200
+    assert len(resp.json()) >= 1
+
+    resp = await client.get(
+        "/api/notes?since=2099-01-01T00:00:00+00:00",
+        headers=auth_header(token),
+    )
+    assert resp.status_code == 200
+    assert len(resp.json()) == 0
+
+
+@pytest.mark.asyncio
+async def test_notes_require_auth(client: AsyncClient):
+    resp = await client.get("/api/notes")
+    assert resp.status_code in (401, 403)
+
+
+# ── Sync ────────────────────────────────────────────────────────────────────
+
+
+@pytest.mark.asyncio
+async def test_sync_push(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    resp = await client.post(
+        "/api/sync/push",
+        json={
+            "notes": [
+                {"id": "sync-1", "title": "Synced", "tags": [], "strokes_json": "[]", "updated_at": "2024-01-01T00:00:00+00:00"},
+                {"id": "sync-2", "title": "Also", "tags": ["t"], "strokes_json": "[]", "updated_at": "2024-01-02T00:00:00+00:00"},
+            ]
+        },
+        headers=auth_header(token),
+    )
+    assert resp.status_code == 200
+    assert resp.json()["synced_count"] == 2
+
+
+@pytest.mark.asyncio
+async def test_sync_pull(client: AsyncClient):
+    token, _ = await register_and_login(client)
+    await client.post(
+        "/api/sync/push",
+        json={"notes": [{"id": "pull-1", "title": "Pull Me", "tags": [], "strokes_json": "[]", "updated_at": "2024-06-01T00:00:00+00:00"}]},
+        headers=auth_header(token),
+    )
+    resp = await client.post(
+        "/api/sync/pull",
+        json={"since": "2024-01-01T00:00:00+00:00"},
+        headers=auth_header(token),
+    )
+    assert resp.status_code == 200
+    notes = resp.json()["notes"]
+    assert len(notes) >= 1
+    assert any(n["id"] == "pull-1" for n in notes)