link watcher switch to event based instead of polling

backend/src/api/network_api.py

@@ -86,10 +86,10 @@ class BridgeRemoveRequest(BaseModel):
 class BridgeLinkStateEnableRequest(BaseModel):
     """Payload for enabling bridge member link-state propagation."""
 
-    poll_interval_seconds: float = Field(
-        settings.bridge_link_state_poll_interval_seconds,
+    recovery_holdoff_seconds: float = Field(
+        settings.bridge_link_state_recovery_holdoff_seconds,
         gt=0,
-        description="Polling interval for member link-state checks.",
+        description="Holdoff before sibling interfaces are restored after recovery.",
     )
 
 
@@ -109,11 +109,12 @@ class BridgeLinkStateWatcherStatus(BaseModel):
 
     bridge: str = Field(..., description="Bridge interface name.")
     active: bool = Field(..., description="Whether the watcher thread is currently active.")
-    poll_interval_seconds: Optional[float] = Field(None, description="Watcher polling interval.")
-    last_poll_ts: Optional[float] = Field(None, description="Unix timestamp of the last poll.")
+    event_driven: Optional[bool] = Field(None, description="Whether the watcher is driven by netlink link events.")
+    last_event_ts: Optional[float] = Field(None, description="Unix timestamp of the last processed event/state evaluation.")
     last_error: Optional[str] = Field(None, description="Most recent watcher error, if any.")
     last_action: Optional[str] = Field(None, description="Most recent propagation action.")
     suppressed_members: List[str] = Field(default_factory=list, description="Members currently forced down by the watcher.")
+    recovery_holdoff_seconds: Optional[float] = Field(None, description="Configured recovery holdoff before restoring siblings.")
     members: Dict[str, BridgeMemberLinkStateInfo] = Field(default_factory=dict, description="Per-member link-state snapshot.")
     message: Optional[str] = Field(None, description="Optional informational message.")
 
@@ -437,7 +438,7 @@ def enable_bridge_link_state_watcher(
 
     status = bridge_link_state_manager.enable(
         bridge_name=bridge_name,
-        poll_interval_seconds=req.poll_interval_seconds,
+        recovery_holdoff_seconds=req.recovery_holdoff_seconds,
     )
     return _watcher_status_response(status)