@remotion/studio-server: Fix deleting the last keyframe

[JonnyBurger]

Fixes #7898

Summary

• Convert single-keyframe removals back to the removed static value instead of generating empty interpolate() calls.
• Update optimistic keyframe deletion state to drop keyframed status when the final keyframe is removed.
• Add regression coverage for sequence props, color props, effect props, and optimistic deletion.

Testing

• bun test src/test/update-keyframes.test.ts in packages/studio-server
• bun test src/test/optimistic-delete-keyframe.test.ts in packages/studio-shared
• One-off codemod repro now outputs width: 320 instead of interpolate(frame, [], [])
• bun run build
• bun run formatting
• bun run stylecheck (fails only on documented local Go 1.22.2 vs @remotion/lambda-go Go >= 1.23 requirement)
• bun run lint in packages/studio-server
• bun run lint in packages/studio-shared
• bun run formatting in packages/studio-server
• bun run formatting in packages/studio-shared

Manual UI note

• Started packages/example Studio successfully, but browser preview manual testing is blocked in this VM by a WebGL/GPU error, so no UI artifact is attached.

  

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Project	Deployment	Actions	Updated (UTC)
bugs	Ready	Preview, Comment	May 31, 2026 8:48pm
remotion	Ready	Preview, Comment	May 31, 2026 8:48pm

[pullfrog]

✅ No new issues found.

Reviewed changes — a focused bugfix for deleting the last keyframe on sequence, color, and effect props, plus regression tests.

• update-keyframes.ts: removeKeyframe now returns the removed keyframe's static output expression when zero keyframes remain, instead of emitting an empty interpolate(frame, [], []) call.
• optimistic-delete-keyframe.ts: removeKeyframeFromPropStatus now returns a canUpdate: true, codeValue status when the last keyframe is removed, instead of keeping a stale keyframed status.
• Tests: Added regression coverage for sequence props, color props, effect props, and optimistic deletion.

  ^{｜ View workflow run ｜ Using Kimi K2 ｜ 𝕏}