feat: git-like project versioning (v1)

Linear per-project history per notes/project-versioning.md: named
checkpoints (thumbnail via renderer.captureFrame) plus auto-checkpoints
on save (60s throttle, ring of 20, named never rotate). Restore writes a
safety checkpoint first, then swaps the document outside undo/redo.
Media assets referenced by any version are pinned against deletion.
Migration v31-v32 stamps the schema; the version store lives in its own
IDB database with an in-memory fallback for tests. Versions popover in
the editor header for jump/rename/delete. 12 new tests.

1 files changed, 87 insertions, 71 deletions

diff --git a/apps/web/src/services/storage/service.ts b/apps/web/src/services/storage/service.ts
index e8fc26c0..7b01f9e5 100644
--- a/apps/web/src/services/storage/service.ts
+++ b/apps/web/src/services/storage/service.ts
@@ -51,6 +51,91 @@ function normalizeBookmarks({ raw }: { raw: unknown }): Bookmark[] {
 		.filter((b): b is Bookmark => b !== null);
 }
 
+function stripAudioBuffers({ tracks }: { tracks: SceneTracks }): SceneTracks {
+	return {
+		...tracks,
+		audio: tracks.audio.map((track) => ({
+			...track,
+			elements: track.elements.map((element) => {
+				const { buffer: _buffer, ...rest } = element;
+				return rest;
+			}),
+		})),
+	};
+}
+
+export function serializeProject({
+	project,
+}: {
+	project: TProject;
+}): SerializedProject {
+	const duration =
+		project.metadata.duration ??
+		getProjectDurationFromScenes({ scenes: project.scenes });
+	const serializedScenes: SerializedScene[] = project.scenes.map((scene) => ({
+		id: scene.id,
+		name: scene.name,
+		isMain: scene.isMain,
+		tracks: stripAudioBuffers({ tracks: scene.tracks }),
+		bookmarks: scene.bookmarks,
+		createdAt: scene.createdAt.toISOString(),
+		updatedAt: scene.updatedAt.toISOString(),
+	}));
+
+	return {
+		metadata: {
+			id: project.metadata.id,
+			name: project.metadata.name,
+			thumbnail: project.metadata.thumbnail,
+			duration,
+			createdAt: project.metadata.createdAt.toISOString(),
+			updatedAt: project.metadata.updatedAt.toISOString(),
+		},
+		scenes: serializedScenes,
+		currentSceneId: project.currentSceneId,
+		settings: project.settings,
+		version: project.version,
+		timelineViewState: project.timelineViewState,
+	};
+}
+
+export function deserializeProject({
+	serialized,
+}: {
+	serialized: SerializedProject;
+}): TProject {
+	const scenes =
+		serialized.scenes?.map((scene) => ({
+			id: scene.id,
+			name: scene.name,
+			isMain: scene.isMain,
+			tracks: scene.tracks,
+			bookmarks: normalizeBookmarks({ raw: scene.bookmarks }),
+			createdAt: new Date(scene.createdAt),
+			updatedAt: new Date(scene.updatedAt),
+		})) ?? [];
+
+	return {
+		metadata: {
+			id: serialized.metadata.id,
+			name: serialized.metadata.name,
+			thumbnail: serialized.metadata.thumbnail,
+			duration: roundMediaTime({
+				time:
+					serialized.metadata.duration ??
+					getProjectDurationFromScenes({ scenes }),
+			}),
+			createdAt: new Date(serialized.metadata.createdAt),
+			updatedAt: new Date(serialized.metadata.updatedAt),
+		},
+		scenes,
+		currentSceneId: serialized.currentSceneId || "",
+		settings: serialized.settings,
+		version: serialized.version,
+		timelineViewState: serialized.timelineViewState,
+	};
+}
+
 class StorageService {
 	private projectsAdapter: IndexedDBAdapter<SerializedProject>;
 	private savedSoundsAdapter: IndexedDBAdapter<SavedSoundsData>;
@@ -118,48 +203,8 @@ class StorageService {
 		return isStorageQuotaExceededError({ error });
 	}
 
-	private stripAudioBuffers({ tracks }: { tracks: SceneTracks }): SceneTracks {
-		return {
-			...tracks,
-			audio: tracks.audio.map((track) => ({
-				...track,
-				elements: track.elements.map((element) => {
-					const { buffer: _buffer, ...rest } = element;
-					return rest;
-				}),
-			})),
-		};
-	}
-
 	async saveProject({ project }: { project: TProject }): Promise<void> {
-		const duration =
-			project.metadata.duration ??
-			getProjectDurationFromScenes({ scenes: project.scenes });
-		const serializedScenes: SerializedScene[] = project.scenes.map((scene) => ({
-			id: scene.id,
-			name: scene.name,
-			isMain: scene.isMain,
-			tracks: this.stripAudioBuffers({ tracks: scene.tracks }),
-			bookmarks: scene.bookmarks,
-			createdAt: scene.createdAt.toISOString(),
-			updatedAt: scene.updatedAt.toISOString(),
-		}));
-
-		const serializedProject: SerializedProject = {
-			metadata: {
-				id: project.metadata.id,
-				name: project.metadata.name,
-				thumbnail: project.metadata.thumbnail,
-				duration,
-				createdAt: project.metadata.createdAt.toISOString(),
-				updatedAt: project.metadata.updatedAt.toISOString(),
-			},
-			scenes: serializedScenes,
-			currentSceneId: project.currentSceneId,
-			settings: project.settings,
-			version: project.version,
-			timelineViewState: project.timelineViewState,
-		};
+		const serializedProject = serializeProject({ project });
 
 		await this.projectsAdapter.set({
 			key: project.metadata.id,
@@ -190,36 +235,7 @@ class StorageService {
 			return null;
 		}
 
-		const scenes =
-			serializedProject.scenes?.map((scene) => ({
-				id: scene.id,
-				name: scene.name,
-				isMain: scene.isMain,
-				tracks: scene.tracks,
-				bookmarks: normalizeBookmarks({ raw: scene.bookmarks }),
-				createdAt: new Date(scene.createdAt),
-				updatedAt: new Date(scene.updatedAt),
-			})) ?? [];
-
-		const project: TProject = {
-			metadata: {
-				id: serializedProject.metadata.id,
-				name: serializedProject.metadata.name,
-				thumbnail: serializedProject.metadata.thumbnail,
-				duration: roundMediaTime({
-					time:
-						serializedProject.metadata.duration ??
-						getProjectDurationFromScenes({ scenes }),
-				}),
-				createdAt: new Date(serializedProject.metadata.createdAt),
-				updatedAt: new Date(serializedProject.metadata.updatedAt),
-			},
-			scenes,
-			currentSceneId: serializedProject.currentSceneId || "",
-			settings: serializedProject.settings,
-			version: serializedProject.version,
-			timelineViewState: serializedProject.timelineViewState,
-		};
+		const project = deserializeProject({ serialized: serializedProject });
 
 		return { project };
 	}