feat(bridge): alt(331f) 写通道——build 4 + CLI raw --channel alt，测试全绿

src/ppclock/bridge.py

@@ -145,6 +145,10 @@ class BridgeTransport:
     async def write_rxtx(self, data: bytes, response: bool = True):
         await self._rpc("write", char="rxtx", data=data.hex(), response=response)
 
+    async def write_alt(self, data: bytes, response: bool = True):
+        """经 331f 通道写（实机证据：1f1f 仅 ATT-ACK，331f 为活命令通道）。"""
+        await self._rpc("write", char="alt", data=data.hex(), response=response)
+
     async def read_rxtx(self) -> bytes:
         return bytes.fromhex((await self._rpc("read", char="rxtx"))["data"])
 

src/ppclock/cli.py

@@ -172,7 +172,7 @@ def build_parser() -> argparse.ArgumentParser:
 
     sp = sub.add_parser("raw", help="高级命令：直发 hex")
     sp.add_argument("hex")
-    sp.add_argument("--channel", default="rxtx", choices=["rxtx", "epd"])
+    sp.add_argument("--channel", default="rxtx", choices=["rxtx", "epd", "alt"])
     sp.add_argument("--no-response", action="store_true")
 
     sp = sub.add_parser("ota", help="SUOTA 固件升级（高危，需确认）")
@@ -255,6 +255,8 @@ async def _run_command(args, t):
         data = bytes.fromhex(args.hex)
         if args.channel == "epd":
             await t.write_epd(data, response=not args.no_response)
+        elif args.channel == "alt":
+            await t.write_alt(data, response=not args.no_response)
         else:
             await t.write_rxtx(data, response=not args.no_response)
         return {"sent": len(data)}