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, 298 insertions, 0 deletions

diff --git a/apps/web/src/services/renderer/webgl-utils.ts b/apps/web/src/services/renderer/webgl-utils.ts
new file mode 100644
index 00000000..834c652e
--- /dev/null
+++ b/apps/web/src/services/renderer/webgl-utils.ts
@@ -0,0 +1,298 @@
+import VERTEX_SHADER_SOURCE from "@/lib/effects/effect.vert.glsl";
+
+export interface EffectPassData {
+	fragmentShader: string;
+	uniforms: Record<string, number | number[]>;
+}
+
+export const QUAD_POSITIONS = new Float32Array([
+	-1, -1, 1, -1, -1, 1, -1, 1, 1, -1, 1, 1,
+]);
+
+export function compileProgram({
+	context,
+	fragmentShaderSource,
+	programCache,
+}: {
+	context: WebGLRenderingContext;
+	fragmentShaderSource: string;
+	programCache: Map<string, WebGLProgram>;
+}): WebGLProgram {
+	const cached = programCache.get(fragmentShaderSource);
+	if (cached) {
+		return cached;
+	}
+	const vertexShader = compileShader({
+		context,
+		source: VERTEX_SHADER_SOURCE,
+		type: context.VERTEX_SHADER,
+	});
+	const fragmentShader = compileShader({
+		context,
+		source: fragmentShaderSource,
+		type: context.FRAGMENT_SHADER,
+	});
+	const program = context.createProgram();
+	if (!program) {
+		throw new Error("Failed to create WebGL program");
+	}
+	context.attachShader(program, vertexShader);
+	context.attachShader(program, fragmentShader);
+	context.linkProgram(program);
+	if (!context.getProgramParameter(program, context.LINK_STATUS)) {
+		const info = context.getProgramInfoLog(program);
+		context.deleteProgram(program);
+		throw new Error(`WebGL program link failed: ${info}`);
+	}
+	context.deleteShader(vertexShader);
+	context.deleteShader(fragmentShader);
+	programCache.set(fragmentShaderSource, program);
+	return program;
+}
+
+export function compileShader({
+	context,
+	source,
+	type,
+}: {
+	context: WebGLRenderingContext;
+	source: string;
+	type: number;
+}): WebGLShader {
+	const shader = context.createShader(type);
+	if (!shader) {
+		throw new Error("Failed to create WebGL shader");
+	}
+	context.shaderSource(shader, source);
+	context.compileShader(shader);
+	if (!context.getShaderParameter(shader, context.COMPILE_STATUS)) {
+		const info = context.getShaderInfoLog(shader);
+		context.deleteShader(shader);
+		throw new Error(`WebGL shader compile failed: ${info}`);
+	}
+	return shader;
+}
+
+export function createTexture({
+	context,
+	source,
+}: {
+	context: WebGLRenderingContext;
+	source: CanvasImageSource;
+}): WebGLTexture {
+	const texture = context.createTexture();
+	if (!texture) {
+		throw new Error("Failed to create WebGL texture");
+	}
+	context.activeTexture(context.TEXTURE0);
+	context.bindTexture(context.TEXTURE_2D, texture);
+	context.pixelStorei(context.UNPACK_FLIP_Y_WEBGL, 1);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_WRAP_S,
+		context.CLAMP_TO_EDGE,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_WRAP_T,
+		context.CLAMP_TO_EDGE,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_MIN_FILTER,
+		context.LINEAR,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_MAG_FILTER,
+		context.LINEAR,
+	);
+	context.texImage2D(
+		context.TEXTURE_2D,
+		0,
+		context.RGBA,
+		context.RGBA,
+		context.UNSIGNED_BYTE,
+		source as TexImageSource,
+	);
+	return texture;
+}
+
+export function setUniforms({
+	context,
+	program,
+	uniforms,
+}: {
+	context: WebGLRenderingContext;
+	program: WebGLProgram;
+	uniforms: Record<string, number | number[]>;
+}): void {
+	for (const [name, value] of Object.entries(uniforms)) {
+		const location = context.getUniformLocation(program, name);
+		if (location === null) continue;
+
+		if (typeof value === "number") {
+			context.uniform1f(location, value);
+		} else if (Array.isArray(value)) {
+			if (value.length === 2) {
+				context.uniform2fv(location, new Float32Array(value));
+			} else if (value.length === 3) {
+				context.uniform3fv(location, new Float32Array(value));
+			} else if (value.length === 4) {
+				context.uniform4fv(location, new Float32Array(value));
+			}
+		}
+	}
+}
+
+export function drawFullscreenQuad({
+	context,
+	program,
+	width,
+	height,
+}: {
+	context: WebGLRenderingContext;
+	program: WebGLProgram;
+	width: number;
+	height: number;
+}): void {
+	const positionLocation = context.getAttribLocation(program, "a_position");
+	const buffer = context.createBuffer();
+	context.bindBuffer(context.ARRAY_BUFFER, buffer);
+	context.bufferData(context.ARRAY_BUFFER, QUAD_POSITIONS, context.STATIC_DRAW);
+	context.enableVertexAttribArray(positionLocation);
+	context.vertexAttribPointer(positionLocation, 2, context.FLOAT, false, 0, 0);
+
+	context.viewport(0, 0, width, height);
+	context.clearColor(0, 0, 0, 0);
+	context.clear(context.COLOR_BUFFER_BIT);
+	context.drawArrays(context.TRIANGLES, 0, 6);
+}
+
+export function createFramebufferTexture({
+	context,
+	width,
+	height,
+}: {
+	context: WebGLRenderingContext;
+	width: number;
+	height: number;
+}): { texture: WebGLTexture; framebuffer: WebGLFramebuffer } {
+	const texture = context.createTexture();
+	if (!texture) throw new Error("Failed to create framebuffer texture");
+	context.bindTexture(context.TEXTURE_2D, texture);
+	context.texImage2D(
+		context.TEXTURE_2D,
+		0,
+		context.RGBA,
+		width,
+		height,
+		0,
+		context.RGBA,
+		context.UNSIGNED_BYTE,
+		null,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_WRAP_S,
+		context.CLAMP_TO_EDGE,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_WRAP_T,
+		context.CLAMP_TO_EDGE,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_MIN_FILTER,
+		context.LINEAR,
+	);
+	context.texParameteri(
+		context.TEXTURE_2D,
+		context.TEXTURE_MAG_FILTER,
+		context.LINEAR,
+	);
+	context.bindTexture(context.TEXTURE_2D, null);
+
+	const framebuffer = context.createFramebuffer();
+	if (!framebuffer) throw new Error("Failed to create framebuffer");
+	context.bindFramebuffer(context.FRAMEBUFFER, framebuffer);
+	context.framebufferTexture2D(
+		context.FRAMEBUFFER,
+		context.COLOR_ATTACHMENT0,
+		context.TEXTURE_2D,
+		texture,
+		0,
+	);
+	context.bindFramebuffer(context.FRAMEBUFFER, null);
+
+	return { texture, framebuffer };
+}
+
+export function applyMultiPassEffect({
+	context,
+	source,
+	width,
+	height,
+	passes,
+	programCache,
+}: {
+	context: WebGLRenderingContext;
+	source: CanvasImageSource;
+	width: number;
+	height: number;
+	passes: EffectPassData[];
+	programCache: Map<string, WebGLProgram>;
+}): void {
+	const sourceTexture = createTexture({ context, source });
+	let currentTexture: WebGLTexture = sourceTexture;
+
+	const intermediates: Array<{
+		texture: WebGLTexture;
+		framebuffer: WebGLFramebuffer;
+	}> = [];
+	for (let i = 0; i < passes.length - 1; i++) {
+		intermediates.push(createFramebufferTexture({ context, width, height }));
+	}
+
+	for (let i = 0; i < passes.length; i++) {
+		const pass = passes[i];
+		const program = compileProgram({
+			context,
+			fragmentShaderSource: pass.fragmentShader,
+			programCache,
+		});
+		const isLastPass = i === passes.length - 1;
+		const targetFramebuffer = isLastPass ? null : intermediates[i].framebuffer;
+
+		context.bindFramebuffer(context.FRAMEBUFFER, targetFramebuffer);
+		// biome-ignore lint/correctness/useHookAtTopLevel: WebGL API method, not a React hook
+		context.useProgram(program);
+		context.activeTexture(context.TEXTURE0);
+		context.bindTexture(context.TEXTURE_2D, currentTexture);
+
+		const uTextureLocation = context.getUniformLocation(program, "u_texture");
+		if (uTextureLocation) {
+			context.uniform1i(uTextureLocation, 0);
+		}
+
+		setUniforms({
+			context,
+			program,
+			uniforms: { ...pass.uniforms, u_resolution: [width, height] },
+		});
+		drawFullscreenQuad({ context, program, width, height });
+
+		if (!isLastPass) {
+			currentTexture = intermediates[i].texture;
+		}
+	}
+
+	context.deleteTexture(sourceTexture);
+	for (const intermediate of intermediates) {
+		context.deleteTexture(intermediate.texture);
+		context.deleteFramebuffer(intermediate.framebuffer);
+	}
+	context.bindTexture(context.TEXTURE_2D, null);
+	context.bindFramebuffer(context.FRAMEBUFFER, null);
+}