feat: introduce WebGL effects system and Blur effect

This implements the foundational architecture for video effects, starting with a multi-pass WebGL rendering pipeline and a customizable Gaussian Blur effect.

Key changes:
- WebGL Engine: Added `raw-loader` for `.glsl` shaders, multi-pass framebuffer rendering, and live offscreen canvas previews.
- Node Architecture: Replaced hardcoded background blur with `CompositeEffectNode` and added `EffectLayerNode` to apply effects to specific visual elements.
- Timeline & DND: Added a new `effect` track type. Upgraded drag-and-drop to support dropping effects directly onto the timeline. Consolidated track constants into a cleaner `TRACK_CONFIG`.
- UI/UX: Added an Effects tab in the assets panel with live previews. Added an Effect Properties panel with sliders and inputs for fine-tuning parameters.
- Data Model: Added `sourceDuration` to video and audio elements, and wrote a v8 storage migration to update existing projects to the new schema.
- Docs: Added `CHANGELOG.md` tracking v0.1.0 and v0.2.0, plus `docs/effects-renderer.md` to document the new WebGL pipeline.

1 files changed, 0 insertions, 75 deletions

diff --git a/apps/web/src/services/renderer/nodes/blur-background-node.ts b/apps/web/src/services/renderer/nodes/blur-background-node.ts
deleted file mode 100644
index 504161d9..00000000
--- a/apps/web/src/services/renderer/nodes/blur-background-node.ts
+++ /dev/null
@@ -1,75 +0,0 @@
-import type { CanvasRenderer } from "../canvas-renderer";
-import { BaseNode } from "./base-node";
-
-export type BlurBackgroundNodeParams = {
-	blurIntensity: number;
-	contentNodes: BaseNode[];
-};
-
-export class BlurBackgroundNode extends BaseNode<BlurBackgroundNodeParams> {
-	private blurIntensity: number;
-	private contentNodes: BaseNode[];
-
-	constructor(params: BlurBackgroundNodeParams) {
-		super(params);
-		this.blurIntensity = params.blurIntensity;
-		this.contentNodes = params.contentNodes;
-	}
-
-	async render({
-		renderer,
-		time,
-	}: {
-		renderer: CanvasRenderer;
-		time: number;
-	}): Promise<void> {
-		let offscreen: OffscreenCanvas | HTMLCanvasElement;
-		let offscreenCtx:
-			| OffscreenCanvasRenderingContext2D
-			| CanvasRenderingContext2D;
-
-		try {
-			offscreen = new OffscreenCanvas(renderer.width, renderer.height);
-			const ctx = offscreen.getContext("2d");
-			if (!ctx) {
-				throw new Error("failed to get offscreen canvas context");
-			}
-			offscreenCtx = ctx;
-		} catch {
-			offscreen = document.createElement("canvas");
-			offscreen.width = renderer.width;
-			offscreen.height = renderer.height;
-			const ctx = offscreen.getContext("2d");
-			if (!ctx) {
-				throw new Error("failed to get canvas context");
-			}
-			offscreenCtx = ctx;
-		}
-
-		const originalContext = renderer.context;
-		renderer.context = offscreenCtx;
-
-		for (const node of this.contentNodes) {
-			await node.render({ renderer, time });
-		}
-
-		renderer.context = originalContext;
-
-		const zoomScale = 1.4;
-		const scaledWidth = renderer.width * zoomScale;
-		const scaledHeight = renderer.height * zoomScale;
-		const offsetX = (renderer.width - scaledWidth) / 2;
-		const offsetY = (renderer.height - scaledHeight) / 2;
-
-		renderer.context.save();
-		renderer.context.filter = `blur(${this.blurIntensity}px)`;
-		renderer.context.drawImage(
-			offscreen as CanvasImageSource,
-			offsetX,
-			offsetY,
-			scaledWidth,
-			scaledHeight,
-		);
-		renderer.context.restore();
-	}
-}