feat(studio): GSAP tween editing in Design panel (#1102)

* feat(studio): GSAP tween editing in Design panel

Add a GSAP animation editor to the studio Design panel: select an element,
view and edit its tweens (properties, easing, timing), add/delete animations,
and drag custom bezier speed curves — all persisted back to the composition
HTML. Gated behind VITE_STUDIO_ENABLE_GSAP_PANEL.

Parsing of existing GSAP source now uses a recast + Babel AST parser instead of
regex, giving scope resolution, stable tween IDs, and round-trip preservation of
extras and unresolved raw values.

recast compiles to CommonJS that calls require("fs"), which breaks browser and
Vite SSR bundles. To contain it, @hyperframes/core is split into an isomorphic
layer and a Node-only AST layer:

- gsapSerialize.ts holds the recast-free helpers (serialization, keyframe
  conversion, validation, shared types). htmlParser.ts is now fully isomorphic.
- parseGsapScript and the script-mutation helpers live in gsapParser.ts,
  reachable only via the @hyperframes/core/gsap-parser subpath, loaded
  server-side by the studio-api mutation routes and the linter via dynamic
  import (recast stays external under SSR).
- The barrel and the gsap-constants subpath are recast-free, so studio browser
  bundles never trace recast.

Adds AST parser unit + stress coverage and e2e helpers for the panel.

* fix(lint): await async lintHyperframeHtml in all callers

lintHyperframeHtml became async (gsap rules use dynamic import)
but lintProject and check-hyperframe-static weren't awaiting it,
causing typecheck failures and runtime crashes in CI.

Also wire LintRule type in gsap rules to fix fallow unused-type
finding, and suppress render.ts exported-for-tests symbols.

packages/studio/src/components/editor/manualEditingAvailability.ts

@@ -65,6 +65,12 @@ export const STUDIO_BLOCKS_PANEL_ENABLED = resolveStudioBooleanEnvFlag(
   true,
 );
 
+export const STUDIO_GSAP_PANEL_ENABLED = resolveStudioBooleanEnvFlag(
+  env,
+  ["VITE_STUDIO_ENABLE_GSAP_PANEL", "VITE_STUDIO_GSAP_PANEL_ENABLED"],
+  false,
+);
+
 export const STUDIO_PREVIEW_SELECTION_ENABLED = STUDIO_INSPECTOR_PANELS_ENABLED;
 
 export const STUDIO_MANUAL_EDITING_DISABLED_TITLE = "Manual editing is temporarily disabled";