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.

schemas/artifacts/decision_log.schema.json

@@ -28,6 +28,7 @@
               "pipeline_selection",
               "provider_selection",
               "renderer_family_selection",
+              "render_runtime_selection",
               "playbook_selection",
               "fallback_decision",
               "budget_tradeoff",

schemas/artifacts/edit_decisions.schema.json

@@ -4,7 +4,7 @@
   "title": "Edit Decisions",
   "description": "Editorial decisions produced by the Edit Agent.",
   "type": "object",
-  "required": ["version", "cuts"],
+  "required": ["version", "cuts", "render_runtime"],
   "properties": {
     "version": { "type": "string", "const": "1.0" },
     "cuts": {
@@ -192,7 +192,12 @@
     "renderer_family": {
       "type": "string",
       "enum": ["explainer-data", "explainer-teacher", "cinematic-trailer", "documentary-montage", "product-reveal", "screen-demo", "presenter", "animation-first"],
-      "description": "Locked at proposal stage — determines which Remotion composition renders this video"
+      "description": "Locked at proposal stage — creative grammar for this deliverable. Preserved from proposal_packet; edit MUST NOT change without a logged decision."
+    },
+    "render_runtime": {
+      "type": "string",
+      "enum": ["remotion", "hyperframes", "ffmpeg"],
+      "description": "Locked at proposal stage — technical runtime that realizes renderer_family. Edit MUST carry this forward unchanged unless a logged render_runtime_selection decision overrides it."
     },
     "slideshow_risk_score": {
       "type": "object",

schemas/artifacts/final_review.schema.json

@@ -82,7 +82,20 @@
           "description": "Delivery promise and renderer governance checks",
           "properties": {
             "delivery_promise_honored": { "type": "boolean" },
-            "renderer_family_used": { "type": "string" },
+            "renderer_family_used": { "type": "string", "description": "Creative grammar that actually ran" },
+            "render_runtime_used": {
+              "type": "string",
+              "enum": ["remotion", "hyperframes", "ffmpeg"],
+              "description": "Technical runtime that actually executed the render. Must match the runtime locked at proposal unless a logged decision overrode it."
+            },
+            "runtime_swap_detected": {
+              "type": "boolean",
+              "description": "True if the runtime that ran differs from the runtime locked in proposal_packet. An unapproved swap is a contract violation."
+            },
+            "runtime_swap_check": {
+              "type": "string",
+              "description": "Human-readable status of the runtime-swap check: 'ok — …', 'detected — …', or 'skipped — …'. When the check was skipped, the reviewer skill is responsible for cross-artifact comparison."
+            },
             "motion_ratio_actual": { "type": "number" },
             "silent_downgrade_detected": { "type": "boolean" },
             "issues": {

schemas/artifacts/proposal_packet.schema.json

@@ -66,7 +66,7 @@
     },
     "production_plan": {
       "type": "object",
-      "required": ["pipeline", "stages"],
+      "required": ["pipeline", "stages", "render_runtime"],
       "properties": {
         "pipeline": { "type": "string", "description": "Pipeline manifest name, e.g., 'animated-explainer'" },
         "playbook": { "type": "string", "description": "Selected style playbook" },
@@ -148,7 +148,12 @@
         "renderer_family": {
           "type": "string",
           "enum": ["explainer-data", "explainer-teacher", "cinematic-trailer", "documentary-montage", "product-reveal", "screen-demo", "presenter", "animation-first"],
-          "description": "Locked at proposal stage — compose cannot change without logging a decision"
+          "description": "Locked at proposal stage — compose cannot change without logging a decision. This is the creative grammar, NOT the technical engine."
+        },
+        "render_runtime": {
+          "type": "string",
+          "enum": ["remotion", "hyperframes", "ffmpeg"],
+          "description": "Locked at proposal stage — the technical runtime that realizes renderer_family. remotion=React scene components, hyperframes=HTML/CSS/GSAP, ffmpeg=simple concat/trim. Must be explicit and auditable; silent swaps are forbidden."
         },
         "music_source": {
           "type": "object",