hyperframes: add HTML/CSS/GSAP as a parallel composition runtime

Separates creative grammar (renderer_family) from technical engine
(render_runtime) so HyperFrames can stand alongside Remotion as a
first-class runtime instead of masquerading as a Remotion sub-case.
Locks runtime choice at proposal stage and enforces it end-to-end: the
schemas require it, video_compose routes by it, the reviewer fails
closed on silent swaps, and a parametrized contract test walks every
pipeline manifest to ensure each planning-stage skill explains the
conversation to the user. Adds hyperframes_compose (scaffold/lint/
validate/render/doctor/add_block), a playbook -> CSS style bridge, and
vendored HyperFrames Layer 3 skills from commit d291358, pinned via
PROVENANCE.md for future re-sync. Final_review now records
render_runtime_used and runtime_swap_detected so compose lies are
catchable after the fact.

skills/pipelines/documentary-montage/compose-director.md

@@ -9,6 +9,14 @@ mix) that makes a mixed-era corpus feel like one film.
 
 The output is a single mp4 plus a `render_report` artifact.
 
+## Runtime Routing (HARD CONSTRAINT)
+
+This pipeline currently REQUIRES `render_runtime="remotion"`. The end-tag stack (ProRes 4444 overlay composited on final scenes, or concat fallback) depends on Remotion's `CinematicRenderer` composition and its alpha-preserving render path. HyperFrames end-tag parity is explicitly Wave 3 / deferred work (see `skills/core/hyperframes.md` → "What stays Remotion-only in Phase 1").
+
+- If `edit_decisions.render_runtime` is anything other than `remotion`, stop. This is a CRITICAL governance violation. Surface the conflict to the user, route the decision back to proposal to re-lock `render_runtime="remotion"`, log a `render_runtime_selection` correction in decision_log, and resume.
+- Never silently proceed by rewriting render_runtime in edit_decisions. The documentary promise (motion-led, mood-driven, uniform grade) is preserved by the Remotion stack, and that promise is what the user approved.
+- Pass `proposal_packet` to `video_compose.execute()` so the in-tool `runtime_swap_detected` check actively confirms the runtime stayed `remotion` end-to-end. A `skipped` check on this pipeline means you forgot to pass the proposal artifact.
+
 ## Prerequisites
 
 | Layer | Resource | Purpose |

skills/pipelines/documentary-montage/idea-director.md

@@ -7,6 +7,12 @@ downstream stage will read. For this pipeline, the brief is the
 thematic core: what the montage is ABOUT, what it should feel like,
 and how long it should run.
 
+## Runtime Selection (MANDATORY — present the constraint, don't silently pick)
+
+Lock `render_runtime = "remotion"`. **HyperFrames is NOT a valid runtime on this pipeline in Phase 1** — documentary-montage depends on the Remotion `CinematicRenderer` composition and its ProRes-4444 alpha end-tag overlay stack, neither of which has HyperFrames parity.
+
+Per AGENT_GUIDE.md → "Present Both Composition Runtimes (HARD RULE)": do NOT silently default. Tell the user: "HyperFrames is available on your machine as an alternative runtime, but documentary-montage depends on the Remotion CinematicRenderer + end-tag overlay stack, so remotion is the only viable choice here — OK to proceed?" Record a `render_runtime_selection` decision in `decision_log` listing both runtimes in `options_considered`, with hyperframes `rejected_because: "CinematicRenderer + end-tag overlay parity deferred on documentary-montage"`.
+
 ## Prerequisites
 
 | Layer | Resource | Purpose |