v0.1.18 — continuous film authoring

This release merges the published 0.1.17 branch with the continuous-film authoring upgrade. The default branch and v0.1.18 now share the merged release commit.

• Whole-film direction, multi-Beat Scene ownership and continuous camera/event motion.
• Explicit authored frame timing with zero TTS, alongside the existing narrated and visual-scene contracts.
• Frozen whole-film preview, presence-aware revision snapshots and single-encode AAC alignment.
• Preserved shared SVG handoffs, bound Scene previews and whole-composition BGM from 0.1.17.
• Updated Workspace-local video Skill and generated guidance, authored chapter review fix and patched transitive dependencies.

Release verification retains exact package fingerprints, affected regressions, type/lint/build, dependency audit, fresh external installation and doctor, a minimal real render with EOF decoding, and npm trusted-publisher provenance. The maintainer explicitly approved reuse of earlier video/native acceptance; fresh merged-package native first use is not claimed.

See the release plan and review scope.