[tt-a1i]

Problem and resulting behavior

Correct rendering alone does not make an animation clear or attractive. New scenes now load visual-direction guidance before coding, formula derivations have explicit term-identity examples, and difficult transitions can be inspected at chosen times in the delivered MP4 without rerunning the scene.

Changes

• Add focused guidance for composition, shot design, correspondence, semantic beats, choreography and visual iteration. Keep detailed references behind a small skill-entrypoint change.
• Add two original CE examples: a head-to-tail vector story, and a labeled Typst derivation that subtracts the same term from both sides and then cancels it. Repeated terms have distinct identities and the equals sign stays anchored.
• Add a standalone video inspector using existing PyAV/Pillow: sample the frame displayed at requested presentation times; save full-resolution PNGs, a readable multirow sheet, actual times/indices and an input hash. The smoke runner shares this implementation; screenshots do not imply visual approval.
• Record pinned-source research and adoption decisions for 14 projects across authoring, formula continuity, preview feedback and render-feedback evaluation. Defer external engines, editor integrations and optional-service plugins where current CE capabilities suffice.
• Archive one fresh-session Chinese heap-repair trial: frozen task/criteria, verbatim source, conditions/hashes, six sampled frames and a parent assessment. It is a macOS/font-specific historical evaluation fixture, not a default cross-platform example or a universal quality benchmark.
• No dependency or lockfile changes; no upstream code/assets bundled. Typst remains the existing optional extra.

Validation

• Local tests: 6 passed, including real encoded videos with irregular timestamps, displayed-frame boundaries, invalid requests, grid layout and CLI full-resolution output.
• Focused smoke renders and shared-inspector integration passed on CE 0.22.0 / Python 3.13.14 / Cairo; optional Typst skipping also checked.
• Both original examples rendered at 1920x1080 / 30 fps and fully decoded (448 vector frames, 340 formula frames); named section clips/metadata exported. Six vector and eight formula transition/settled frames inspected. Cancellation marks now disappear before retained terms move through them.
• Final head 187e647 passed both CI jobs: 17 scenes on Python 3.11 and 18 on 3.13, plus all 6 tests on each job. Final CI run. Shared-inspector output was also checked against downloaded reports/media hashes and multirow sheet dimensions.
• Fresh trial: 1280x720 / 30 fps / 20.10 s, 603 frames decoded. Parent independently checked the reference heap-repair path, sampled visual correspondence, source/media hashes and delivery metadata. Earlier authoring fixes are agent-reported; initial versions were not separately available for a before/after assessment.
• Normal-speed playback, comparative aesthetic evaluation, learner testing and external-runtime compatibility benchmarks were not performed. The archived macOS trial is separate from the portable examples scanned by CI.

Dependency

Builds on the CE 0.22 environment and verification infrastructure merged in #2. No package release is included.