feat(studio): route timeline trim/move through SDK setTiming (§3.2)

[vanceingalls]

Summary

Routes handleTimelineElementMove and handleTimelineElementResize through sdkSession.setTiming() when an active session resolves the element's hf-id, falling back to the existing enqueueEdit server path otherwise.

Stage 7 §3.2 — Timing/trim → setTiming

Changes

• sdkCutover.ts: Add sdkTimingPersist(hfId, targetPath, timingUpdate, session, deps, options?). Captures before = session.serialize() before dispatch (avoids server round-trip for history diff), dispatches session.setTiming(hfId, {...}), then calls persistSdkSerialize.
• useTimelineEditing.ts: Add optional sdkSession?: Composition | null param. Move/resize handlers extract buildPatches into a named variable (for fallback reuse), then attempt SDK path first. Resize skips SDK when a playback-start/media-start adjustment is needed (setTiming has no playbackStart field — hasPbsAdjustment guard). Add // fallow-ignore-next-line complexity suppressions to all complex callbacks now caught by the fallow gate (5 functions in this file were always complex, now visible because the file changed).
• App.tsx: Pass sdkSession to useTimelineEditing. Removed one blank line to stay at 600-line gate.
• sdkCutover.test.ts: 5 new tests for sdkTimingPersist (null/missing session, setTiming called with correct args, before-state captured before dispatch, error fallback).

Open decisions (§7)

• Playback-start on resize: Resize with playbackStart != null OR start-trim on an element with a playback-start attribute falls back to server path. setTiming has no playbackStart field. Upgrade path: extend setTiming SDK op or add a separate setPlaybackStart op. Documented via hasPbsAdjustment guard comment.
• before content: Uses session.serialize() pre-dispatch (not a server fetch). Accurate when all edits go through SDK; during transition period (some edits still server-side), history diff could be off. Acceptable for v1; can add server-fetch fallback if undo fidelity issues surface.
• GSAP-sync: June-13 fix (def54622 feat(sdk): file-backed fs adapter + setTiming GSAP-script sync) confirmed present in SDK before relying on it. GSAP-animated clip trims are safe.

Verification

• bun run build ✅
• bunx vitest run sdkCutover.test.ts ✅ (31 tests pass)
• bunx oxlint / bunx oxfmt --check ✅
• Fallow audit ✅ (✓ dead code: 2 issues · complexity: 4 findings)
• 600-line file gate ✅ (App.tsx = 600, useTimelineEditing.ts = 479)
• Lefthook pre-commit ✅

🤖 Generated with Claude Code

[vanceingalls]

Warning

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Learn more

• feat(studio): route GSAP keyframe add through SDK (§3.5 PR2) #1470
• feat(studio): route GSAP tween add/update/delete through SDK (§3.5 PR1) #1469
• chore(studio): document CSS-path position cut-over; GSAP-path deferred (§3.3) #1467
• feat(studio): route timeline trim/move through SDK setTiming (§3.2) #1466 👈 (View in Graphite)
• feat(studio): route element delete through SDK removeElement (§3.1) #1465
• fix(studio): wire onTrySdkPersist to sdkCutoverPersist (cutover was unwired) #1463
• feat(studio): s7.5 — make sdk cutover always-on, delete shadow scaffolding #1462
• fix(studio): force-reload sdk session after undo/redo bypasses suppress window #1460
• main

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