feat: lens effects tab, standalone motion effects, clip/asset rename, preview popout

- New Lens category in the assets panel: Blur, Motion Blur, Zoom In/Out,
  Pan x4, Shake, Pulse, Spin, Custom Zoom. EffectDefinition gains a
  category field; tabs with an empty category are hidden, and the
  properties-panel 'Open effects' button opens the first non-empty one.
- Motion effects work standalone: dropping them on the timeline creates
  an effect-track element that animates (scale/translate/rotate) every
  track below it, computed purely in the TS frame descriptor - no wasm
  changes, identical in preview and export. supportsStandalone removed.
- Motion Blur: directional gaussian smear (amount + angle) reusing the
  existing WGSL shader with arbitrary u_direction.
- Custom Zoom: start/end scale params (keyframable clip-level).
- MotionOffset gains optional rotate, accumulated clip-level and applied
  to standalone layer quads via rotationDegrees.
- Rename clips (timeline context menu) and media assets (media panel
  context menu) via a shared RenameDialog; asset rename persists through
  storageService with rollback on error.
- Preview pops out into a Document Picture-in-Picture window and docks
  back; button hidden where the API is unsupported.
- Export keeps running when the export popover is closed; only the
  explicit Cancel button aborts.
- Captions and Adjustment tabs removed from the assets panel.

1 files changed, 67 insertions, 0 deletions

diff --git a/apps/web/src/effects/definitions/motion-blur.ts b/apps/web/src/effects/definitions/motion-blur.ts
new file mode 100644
index 00000000..b20e6c26
--- /dev/null
+++ b/apps/web/src/effects/definitions/motion-blur.ts
@@ -0,0 +1,67 @@
+import type { EffectDefinition } from "@/effects/types";
+import { GAUSSIAN_BLUR_SHADER, intensityToSigma } from "./blur";
+
+const MAX_SINGLE_PASS_SIGMA = 10;
+const MIN_SIGMA = 0.001;
+
+function parseNumericParam({
+	effectParams,
+	key,
+}: {
+	effectParams: Record<string, unknown>;
+	key: string;
+}): number {
+	const raw = effectParams[key];
+	return typeof raw === "number" ? raw : Number.parseFloat(String(raw));
+}
+
+export const motionBlurEffectDefinition: EffectDefinition = {
+	type: "motion-blur",
+	name: "Motion Blur",
+	keywords: ["motion blur", "smear", "directional", "speed", "streak"],
+	category: "lens",
+	params: [
+		{
+			key: "amount",
+			label: "Amount",
+			type: "number",
+			default: 40,
+			min: 0,
+			max: 100,
+			step: 1,
+		},
+		{
+			key: "angle",
+			label: "Angle",
+			type: "number",
+			default: 0,
+			min: -180,
+			max: 180,
+			step: 1,
+		},
+	],
+	renderer: {
+		passes: [],
+		buildPasses: ({ effectParams, width }) => {
+			const sigma = intensityToSigma({
+				intensity: parseNumericParam({ effectParams, key: "amount" }),
+				resolution: width,
+				reference: 1920,
+			});
+			if (sigma < MIN_SIGMA) return [];
+
+			const angleRad =
+				(parseNumericParam({ effectParams, key: "angle" }) * Math.PI) / 180;
+			return [
+				{
+					shader: GAUSSIAN_BLUR_SHADER,
+					uniforms: {
+						u_sigma: Math.min(sigma, MAX_SINGLE_PASS_SIGMA),
+						u_step: Math.max(1, sigma / MAX_SINGLE_PASS_SIGMA),
+						u_direction: [Math.cos(angleRad), Math.sin(angleRad)],
+					},
+				},
+			];
+		},
+	},
+};