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.

2 files changed, 142 insertions, 26 deletions

diff --git a/apps/web/src/components/editor/panels/properties/effect-properties.tsx b/apps/web/src/components/editor/panels/properties/effect-properties.tsx
new file mode 100644
index 00000000..bf137291
--- /dev/null
+++ b/apps/web/src/components/editor/panels/properties/effect-properties.tsx
@@ -0,0 +1,103 @@
+"use client";
+
+import type { EffectElement } from "@/types/timeline";
+import type { EffectParamDefinition } from "@/types/effects";
+import { getEffect } from "@/lib/effects/registry";
+import { useEditor } from "@/hooks/use-editor";
+import { clamp } from "@/utils/math";
+import { Section, SectionContent, SectionHeader, SectionField, SectionFields } from "./section";
+import { Slider } from "@/components/ui/slider";
+import { NumberField } from "@/components/ui/number-field";
+import { usePropertyDraft } from "./hooks/use-property-draft";
+
+function EffectParamField({
+	param,
+	element,
+	trackId,
+}: {
+	param: EffectParamDefinition;
+	element: EffectElement;
+	trackId: string;
+}) {
+	const editor = useEditor();
+
+	const currentValue = Number(element.params[param.key] ?? param.default);
+	const min = param.min ?? 0;
+	const max = param.max ?? 100;
+	const step = param.step ?? 1;
+
+	const updateParam = (value: number) =>
+		editor.timeline.previewElements({
+			updates: [
+				{
+					trackId,
+					elementId: element.id,
+					updates: { params: { ...element.params, [param.key]: value } },
+				},
+			],
+		});
+
+	const commitParam = () => editor.timeline.commitPreview();
+
+	const draft = usePropertyDraft({
+		displayValue: String(currentValue),
+		parse: (input) => {
+			const parsed = parseFloat(input);
+			if (Number.isNaN(parsed)) return null;
+			return clamp({ value: parsed, min, max });
+		},
+		onPreview: updateParam,
+		onCommit: commitParam,
+	});
+
+	return (
+		<SectionField label={param.label}>
+			<div className="flex items-center gap-3">
+				<Slider
+					className="flex-1"
+					min={min}
+					max={max}
+					step={step}
+					value={[currentValue]}
+					onValueChange={([value]) => updateParam(value)}
+					onValueCommit={commitParam}
+				/>
+				<NumberField
+					className="w-16 shrink-0"
+					value={draft.displayValue}
+					onFocus={draft.onFocus}
+					onChange={draft.onChange}
+					onBlur={draft.onBlur}
+				/>
+			</div>
+		</SectionField>
+	);
+}
+
+export function EffectProperties({
+	element,
+	trackId,
+}: {
+	element: EffectElement;
+	trackId: string;
+}) {
+	const definition = getEffect({ effectType: element.effectType });
+
+	return (
+		<Section hasBorderTop={false}>
+			<SectionHeader title={definition.name} />
+			<SectionContent>
+				<SectionFields>
+					{definition.params.map((param) => (
+						<EffectParamField
+							key={param.key}
+							param={param}
+							element={element}
+							trackId={trackId}
+						/>
+					))}
+				</SectionFields>
+			</SectionContent>
+		</Section>
+	);
+}
diff --git a/apps/web/src/components/editor/panels/properties/index.tsx b/apps/web/src/components/editor/panels/properties/index.tsx
index 4f285f84..75dd81a9 100644
--- a/apps/web/src/components/editor/panels/properties/index.tsx
+++ b/apps/web/src/components/editor/panels/properties/index.tsx
@@ -4,9 +4,37 @@ import { ScrollArea } from "@/components/ui/scroll-area";
 import { AudioProperties } from "./audio-properties";
 import { VideoProperties } from "./video-properties";
 import { TextProperties } from "./text-properties";
+import { EffectProperties } from "./effect-properties";
 import { EmptyView } from "./empty-view";
 import { useEditor } from "@/hooks/use-editor";
 import { useElementSelection } from "@/hooks/timeline/element/use-element-selection";
+import type { TimelineElement, TimelineTrack } from "@/types/timeline";
+
+function ElementProperties({
+	track,
+	element,
+}: {
+	track: TimelineTrack;
+	element: TimelineElement;
+}) {
+	if (element.type === "text") {
+		return <TextProperties element={element} trackId={track.id} />;
+	}
+	if (element.type === "audio") {
+		return <AudioProperties _element={element} />;
+	}
+	if (
+		element.type === "video" ||
+		element.type === "image" ||
+		element.type === "sticker"
+	) {
+		return <VideoProperties element={element} trackId={track.id} />;
+	}
+	if (element.type === "effect") {
+		return <EffectProperties element={element} trackId={track.id} />;
+	}
+	return null;
+}
 
 export function PropertiesPanel() {
 	const editor = useEditor();
@@ -16,34 +44,19 @@ export function PropertiesPanel() {
 		elements: selectedElements,
 	});
 
+	const hasSelection = selectedElements.length > 0;
+
 	return (
-		<div className="panel bg-background h-full rounded-sm border border-t-0 overflow-hidden">
-			{selectedElements.length > 0 ? (
+		<div className="panel bg-background h-full rounded-sm border overflow-hidden">
+			{hasSelection ? (
 				<ScrollArea className="h-full scrollbar-hidden">
-					{elementsWithTracks.map(({ track, element }) => {
-						if (element.type === "text") {
-							return (
-								<div key={element.id}>
-									<TextProperties element={element} trackId={track.id} />
-								</div>
-							);
-						}
-						if (element.type === "audio") {
-							return <AudioProperties key={element.id} _element={element} />;
-						}
-						if (
-							element.type === "video" ||
-							element.type === "image" ||
-							element.type === "sticker"
-						) {
-							return (
-								<div key={element.id}>
-									<VideoProperties element={element} trackId={track.id} />
-								</div>
-							);
-						}
-						return null;
-					})}
+					{elementsWithTracks.map(({ track, element }) => (
+						<ElementProperties
+							key={element.id}
+							track={track}
+							element={element}
+						/>
+					))}
 				</ScrollArea>
 			) : (
 				<EmptyView />