perf(wifi): one status fetch per monitor tick instead of three (#411)

* perf(wifi): one status fetch per monitor tick instead of three

The wifi monitor daemon fetched WiFi status + ethernet state before its
AP-mode check, the check internally fetched the same state again (with
retry), and the daemon fetched a third time afterwards — each fetch is
several nmcli subprocess forks, every 30s, forever, even on a perfectly
healthy link.

check_and_manage_ap_mode's decision logic is extracted to
_manage_ap_mode(status, ethernet, ap_active); the new
check_and_manage_ap_mode_with_state() runs the single (retrying) fetch
battery and returns (changed, status, ethernet, ap_active_after) — the
post-state is derivable because state only ever flips via one enable or
one disable. The original bool-returning method delegates, so existing
callers are untouched. The daemon's dead pre-fetch is removed and its
post-check reads use the returned state; the AP-enable retry semantics
(_get_wifi_status_with_retry) are preserved exactly. ~10-15 forks/30s
drops to ~4-6.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FqzC1nzTWL4kaqgMaQZFam

* fix(wifi): add missing type hints on AP-mode state helpers, fix unused-var lint in tests

- check_and_manage_ap_mode_with_state now declares its
  Tuple[bool, WiFiStatus, bool, bool] return type instead of being untyped.
- _manage_ap_mode's status/ethernet_connected/ap_active parameters are now
  typed (WiFiStatus, bool, bool), matching its existing -> bool return hint.
- test_wifi_check_state.py: rename unused unpacked variables (status/
  ethernet/ap_after) to underscore-prefixed names at the three call sites
  that don't use them, leaving the used ones untouched.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KEZK1P1Q1fu5pcuVrkrCFZ

---------

Co-authored-by: Chuck <chuck@example.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

src/wifi_manager.py

@@ -2564,11 +2564,35 @@ address=/detectportal.firefox.com/192.168.4.1
         Returns:
             True if AP mode state changed, False otherwise
         """
+        changed, _status, _ethernet, _ap = self.check_and_manage_ap_mode_with_state()
+        return changed
+
+    def check_and_manage_ap_mode_with_state(self) -> Tuple[bool, WiFiStatus, bool, bool]:
+        """Like check_and_manage_ap_mode, but also returns the state it
+        observed, so callers (the wifi monitor daemon) don't have to re-run
+        the same nmcli subprocess battery before AND after the check —
+        each status fetch is several process forks.
+
+        Returns:
+            (state_changed, WiFiStatus, ethernet_connected, ap_active_after)
+        """
         try:
             # Get status with retry for more reliable detection
             status = self._get_wifi_status_with_retry()
             ethernet_connected = self._is_ethernet_connected()
             ap_active = self._is_ap_mode_active()
+            changed = self._manage_ap_mode(status, ethernet_connected, ap_active)
+            # State only ever changes via one enable or one disable, so the
+            # post-state is the inverse of the pre-state when changed.
+            ap_after = (not ap_active) if changed else ap_active
+            return changed, status, ethernet_connected, ap_after
+        except Exception as e:
+            logger.error(f"Error checking AP mode: {e}", exc_info=True)
+            return False, WiFiStatus(connected=False), False, False
+
+    def _manage_ap_mode(self, status: WiFiStatus, ethernet_connected: bool, ap_active: bool) -> bool:
+        """AP-mode decision logic against an already-fetched state snapshot."""
+        try:
             auto_enable = self.config.get("auto_enable_ap_mode", True)  # Default: True (safe due to grace period)
             
             # Log current state for debugging