feat(perception): resume full graph on fresh input without restarting models

src/k1link/perception/streaming_lifecycle.py

@@ -227,8 +227,10 @@ class StreamingLifecycle:
             self._check(start)
             if self.continuity is None or self._source_clock_ns is None:
                 raise ValueError("resumable input was not enabled")
-            if any(self._active.values()) or (
-                self._ingress_thread is not None and self._ingress_thread.is_alive()
+            if (
+                not self.mailbox.epoch_drained
+                or any(self._active.values())
+                or (self._ingress_thread is not None and self._ingress_thread.is_alive())
             ):
                 raise StreamSuspended("old epoch callbacks or connection still active")
             if self.continuity.phase != "waiting":

src/k1link/perception/streaming_queue.py

@@ -228,3 +228,9 @@ class StreamMailbox:
             if self.done or self._owned or self.external_pending:
                 raise ValueError("old epoch still owns work or mailbox is closed")
             self._last_sequence = -1
+
+    @property
+    def epoch_drained(self) -> bool:
+        """Resident scratch may remain; no old input/result may still be owned."""
+        with self.condition:
+            return not self.done and not self._owned and not self.external_pending