feat: major editor overhaul (assets, properties, timeline, fonts) (#709)

* feat: major editor overhaul (assets, properties, timeline, fonts)

Refactor editor core systems to standardize UI architecture and improve performance.

Assets & Properties:
- Replace monolithic property items with composable `Section` architecture.
- Add specialized sections for Transform, Blending, and Text.
- Implement `NumberField` with scrubbing and math evaluation.
- Add new ColorPicker with EyeDropper and multiple format support.
- Standardize asset panels using new `PanelView` layout.

Fonts & Stickers:
- Implement custom font atlas/sprite system for high-performance previews.
- Add virtualized FontPicker with search and favorites.
- Refactor stickers to use a provider-based architecture (icons, emoji, flags, shapes).
- Standardize sticker IDs to `provider:value` format.

Timeline & Interaction:
- Convert bookmarks to rich objects with notes, colors, and duration.
- Refactor drag-and-drop to use Command pattern (enabling proper undo/redo).
- Add Shift modifier to disable snapping during moves/resizes.
- Add new overlays for layout guides and text editing.

Renderer:
- Add support for multi-line text, custom line-height, and letter-spacing.
- Implement global composite operation (blend modes).
- Update sticker node to resolve dynamic provider IDs.

Infrastructure:
- Add storage migrations (v3->v6) for text weights, sticker IDs, and bookmarks.
- Update global styles and core UI components (Button, Input, Popover).

* add ts-nocheck directive to settings-legacy.tsx to suppress TypeScript errors

* fix: correct global composite operation assignment in TextNode to ensure proper blend mode handling

* deleted shadcn components with errors

* formatting

* fix linter issues

* migrate from next middleware to proxy

* add missing component back

* add breadcrumb back

* chore: add @radix-ui/react-primitive deps

* chore: more deps

* chore: add missing env vars to bun-ci

* next env

apps/web/src/core/managers/timeline-manager.ts

@@ -23,12 +23,14 @@ import {
 	PasteCommand,
 	UpdateElementStartTimeCommand,
 	MoveElementCommand,
+	TracksSnapshotCommand,
 } from "@/lib/commands/timeline";
-import { BatchCommand } from "@/lib/commands";
+import { BatchCommand, PreviewTracker } from "@/lib/commands";
 import type { InsertElementParams } from "@/lib/commands/timeline/element/insert-element";
 
 export class TimelineManager {
 	private listeners = new Set<() => void>();
+	private previewTracker = new PreviewTracker<TimelineTrack[]>();
 
 	constructor(private editor: EditorCore) {}
 
@@ -214,7 +216,8 @@ export class TimelineManager {
 			({ trackId, elementId, updates: elementUpdates }) =>
 				new UpdateElementCommand(trackId, elementId, elementUpdates),
 		);
-		const command = commands.length === 1 ? commands[0] : new BatchCommand(commands);
+		const command =
+			commands.length === 1 ? commands[0] : new BatchCommand(commands);
 		if (pushHistory) {
 			this.editor.command.execute({ command });
 		} else {
@@ -222,6 +225,52 @@ export class TimelineManager {
 		}
 	}
 
+	isPreviewActive(): boolean {
+		return this.previewTracker.isActive();
+	}
+
+	previewElements({
+		updates,
+	}: {
+		updates: Array<{
+			trackId: string;
+			elementId: string;
+			updates: Partial<Record<string, unknown>>;
+		}>;
+	}): void {
+		const tracks = this.getTracks();
+		this.previewTracker.begin({ state: tracks });
+
+		let updatedTracks = tracks;
+		for (const { trackId, elementId, updates: elementUpdates } of updates) {
+			updatedTracks = updatedTracks.map((track) => {
+				if (track.id !== trackId) return track;
+				const newElements = track.elements.map((element) =>
+					element.id === elementId
+						? { ...element, ...elementUpdates }
+						: element,
+				);
+				return { ...track, elements: newElements } as TimelineTrack;
+			});
+		}
+		this.updateTracks(updatedTracks);
+	}
+
+	commitPreview(): void {
+		const snapshot = this.previewTracker.end();
+		if (snapshot === null) return;
+		const currentTracks = this.getTracks();
+		const command = new TracksSnapshotCommand(snapshot, currentTracks);
+		this.editor.command.push({ command });
+	}
+
+	discardPreview(): void {
+		const snapshot = this.previewTracker.end();
+		if (snapshot !== null) {
+			this.updateTracks(snapshot);
+		}
+	}
+
 	duplicateElements({
 		elements,
 	}: {