Note editor sidebar, full-doc assist, persistent drafts, version history

NoteEditorView: two-column sidebar layout (project/milestone/tags/assist
always visible), removed assist toggle button, InlineAssistPanel removed.

Writing assist: whole_doc mode rewrites entire document; DiffView.vue
replaces editor during review showing full-document diff. Scope dropdown
in sidebar switches between whole-document and section modes.

Persistent drafts: migration 0022 adds note_drafts (UNIQUE per note+user)
and note_versions (max 20, auto-pruned) tables. Draft saved after generation
completes, restored on editor mount, cleared on accept/reject. Version
snapshot created automatically whenever note body changes on save.

HistoryPanel.vue: version list + DiffView modal, restore button writes
body back to editor.

Config: OLLAMA_NUM_CTX default raised to 65536; assist num_predict now
tracks Config.OLLAMA_NUM_CTX instead of a hardcoded 4096.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/fabledassistant/services/note_versions.py

@@ -0,0 +1,51 @@
+from sqlalchemy import select, text
+
+from fabledassistant.models import async_session
+from fabledassistant.models.note_version import NoteVersion
+
+MAX_VERSIONS = 20
+
+
+async def create_version(user_id: int, note_id: int, body: str, title: str) -> NoteVersion:
+    async with async_session() as session:
+        version = NoteVersion(note_id=note_id, user_id=user_id, body=body, title=title)
+        session.add(version)
+        await session.commit()
+        await session.refresh(version)
+
+        # Prune versions beyond MAX_VERSIONS
+        await session.execute(
+            text("""
+                DELETE FROM note_versions
+                WHERE id IN (
+                    SELECT id FROM note_versions
+                    WHERE note_id = :note_id AND user_id = :user_id
+                    ORDER BY created_at DESC
+                    OFFSET :max_versions
+                )
+            """).bindparams(note_id=note_id, user_id=user_id, max_versions=MAX_VERSIONS)
+        )
+        await session.commit()
+        return version
+
+
+async def list_versions(user_id: int, note_id: int) -> list[NoteVersion]:
+    async with async_session() as session:
+        result = await session.execute(
+            select(NoteVersion)
+            .where(NoteVersion.note_id == note_id, NoteVersion.user_id == user_id)
+            .order_by(NoteVersion.created_at.desc())
+        )
+        return list(result.scalars().all())
+
+
+async def get_version(user_id: int, note_id: int, version_id: int) -> NoteVersion | None:
+    async with async_session() as session:
+        result = await session.execute(
+            select(NoteVersion).where(
+                NoteVersion.id == version_id,
+                NoteVersion.note_id == note_id,
+                NoteVersion.user_id == user_id,
+            )
+        )
+        return result.scalars().first()