feat: add apply and verify sync workflow

Makefile

@@ -14,7 +14,7 @@ else
   PIP_INSTALL = $(PIP) install
 endif
 
-.PHONY: install install-cpu install-rocm install-cuda extract ast clean help
+.PHONY: install install-cpu install-rocm install-cuda extract ast sync verify clean help
 
 help:
 	@echo "Targets:"
@@ -24,6 +24,8 @@ help:
 	@echo "  make install-cuda   # force CUDA torch"
 	@echo "  make extract        # run extract.py (uses config.toml if present)"
 	@echo "  make ast            # run sync_audio_test.py (audio_sync_test, PyQtGraph GUI)"
+	@echo "  make sync LAG=0.042 # run apply_sync.py to mux synced output (LAG in seconds)"
+	@echo "  make verify LAG=0.042  # verify sync: video + dual waveform player"
 	@echo "  make clean"
 
 install:
@@ -78,6 +80,12 @@ install-cuda:
 extract:
 	@if [ -x $(PY) ]; then $(PY) extract.py; else python3 extract.py; fi
 
+sync:
+	@if [ -x $(PY) ]; then $(PY) apply_sync.py --config $(CONFIG) --lag $(LAG); else python3 apply_sync.py --config $(CONFIG) --lag $(LAG); fi
+
+verify:
+	@if [ -x $(PY) ]; then QT_STYLE_OVERRIDE=Fusion $(PY) verify_sync.py --config $(CONFIG) --lag $(LAG); else QT_STYLE_OVERRIDE=Fusion python3 verify_sync.py --config $(CONFIG) --lag $(LAG); fi
+
 ast:
 	@AUDIO_A=$$(python3 -c "import tomllib; c=tomllib.load(open('config.toml','rb')); print(c['extract'].get('file_a',''))" 2>/dev/null); \
 	AUDIO_B=$$(python3 -c "import tomllib; c=tomllib.load(open('config.toml','rb')); print(c['extract'].get('file_b',''))" 2>/dev/null); \