refactor: persist stream selection in .stream_state instead of config.toml

extract.py

@@ -493,33 +493,23 @@ for _file_idx, INPUT_FILE in enumerate(INPUT_FILES):
     print(f"-" * 50)
 print(f"All done. Files are in:", OUT_DIR)
 
-# ─── Save selected audio stream indices to config.toml ───
-if len(_audio_stream_selections) >= 2 and CONFIG_PATH and os.path.exists(CONFIG_PATH):
+# ─── Save selected audio stream indices to .stream_state (gitignored) ───
+if len(_audio_stream_selections) >= 2:
     try:
-        with open(CONFIG_PATH, "r") as f:
-            cfg_text = f.read()
-        # Update or add audio_stream_a and audio_stream_b in [extract] section
-        import re
-        def _cfg_set(key: str, val) -> str:
-            nonlocal cfg_text
-            pat = re.compile(rf'(^{key}\s*=\s*).*$')
-            replacement = f'{key} = {val}'
-            if pat.search(cfg_text):
-                cfg_text = pat.sub(replacement, cfg_text, count=1)
-            else:
-                # Insert before the next section header or at end of [extract]
-                ins_pat = re.compile(r'(\[audio\])')
-                if ins_pat.search(cfg_text):
-                    cfg_text = ins_pat.sub(f'{replacement}\n\n\\1', cfg_text, count=1)
-                else:
-                    cfg_text += f"\n{replacement}\n"
-        _cfg_set("audio_stream_a", _audio_stream_selections[0]
-                 if _audio_stream_selections[0] is not None else "null")
-        _cfg_set("audio_stream_b", _audio_stream_selections[1]
-                 if _audio_stream_selections[1] is not None else "null")
-        with open(CONFIG_PATH, "w") as f:
-            f.write(cfg_text)
-        print(f"[config] saved audio_stream_a={_audio_stream_selections[0]}, "
-              f"audio_stream_b={_audio_stream_selections[1]} → {CONFIG_PATH}")
+        import json
+        state_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), ".stream_state")
+        state = {}
+        if os.path.exists(state_path):
+            with open(state_path, "r") as f:
+                state = json.load(f)
+        # Record which files these selections belong to
+        state["file_a"] = INPUT_FILES[0]
+        state["file_b"] = INPUT_FILES[1]
+        for i, sel in enumerate(_audio_stream_selections):
+            key = f"audio_stream_{chr(ord('a') + i)}"
+            state[key] = sel if sel is not None else None
+        with open(state_path, "w") as f:
+            json.dump(state, f, indent=2)
+        print(f"[state] saved stream selection → {state_path}")
     except Exception as e:
-        print(f"[config] warn: could not save stream indices: {e}", file=sys.stderr)
+        print(f"[state] warn: could not save stream indices: {e}", file=sys.stderr)