Add synchronized music-video production planning

Add measured-audio, timed-lyrics, H3 lane planning, identity relay, upload-song routing, model-specific camera contracts, LTX long-horizon planning, workflow migrations, the validated V6 example, regression coverage, and an Unreleased changelog.

scripts/smoke_prompt_builder.py

@@ -212,7 +212,7 @@ def test_minimax_h3_contract_and_splitter_compatibility():
         "continuity ledger",
         "generic real animals",
         "prior shot's resulting position and state",
-        "shot size, angle, or the word handheld alone is not a camera path",
+        "an incoming cut, shot size, angle, subject framing",
         "event-specific sound immediately beside its visible cause",
         "the final frame holds on",
     ):
@@ -559,13 +559,9 @@ def test_minimax_h3_ref2va_contract():
             default_t2va_prompt,
             {"minimax_h3_ref_sections_invalid"},
         ),
-        (
-            ref_prompt.replace("<Audio 1>", "the soundtrack"),
-            {"minimax_h3_ref_missing_asset_tag"},
-        ),
         (
             ref_prompt.replace("<Video 1>", "<Video 2>"),
-            {"minimax_h3_ref_missing_asset_tag", "minimax_h3_ref_undefined_tag"},
+            {"minimax_h3_ref_undefined_tag"},
         ),
         (
             ref_prompt.replace(
@@ -575,23 +571,29 @@ def test_minimax_h3_ref2va_contract():
             ),
             {"minimax_h3_ref_subject_definition_invalid"},
         ),
-        (
-            invalid_subject_usage_prompt,
-            {"minimax_h3_ref_subject_usage_invalid"},
-        ),
-        (
-            ref_prompt.replace("fully_preserved", "preserved", 1),
-            {"minimax_h3_ref_retention_invalid"},
-        ),
     )
     for invalid_prompt, expected_reasons in invalid_prompts:
         invalid_packet = _packet("", {"ready_for_generation": True, "blocked_reasons": []}, segments=[])
         invalid_packet["minimax_h3_prompt"] = invalid_prompt
         invalid_result = _split(invalid_packet, context=context, target=target)
         invalid_metadata = _metadata(invalid_result)
-        assert invalid_result[13] == "", invalid_metadata
+        assert invalid_result[13] == "", (expected_reasons, invalid_metadata)
         assert expected_reasons.issubset(set(invalid_metadata["blocked_reasons"])), invalid_metadata
 
+    repairable_prompts = (
+        invalid_subject_usage_prompt,
+        ref_prompt.replace("fully_preserved", "preserved", 1),
+        ref_prompt.replace("<Audio 1>", "the soundtrack"),
+    )
+    for repairable_prompt in repairable_prompts:
+        repairable_packet = _packet("", {"ready_for_generation": True, "blocked_reasons": []}, segments=[])
+        repairable_packet["minimax_h3_prompt"] = repairable_prompt
+        repairable_result = _split(repairable_packet, context=context, target=target)
+        repairable_metadata = _metadata(repairable_result)
+        assert repairable_result[13], repairable_metadata
+        assert repairable_result[12] is True, repairable_metadata
+        assert repairable_metadata["blocked_reasons"] == [], repairable_metadata
+
 
 def test_minimax_h3_ref2va_structure_repair_and_generation_gate():
     manifest = (