M1 step 6: Wi-Fi Tools from ordinary scans

- lib/wifi (host-tested): channel occupancy (neighbour spill, signal
  weighting, quietest of 1/6/11) and a signal tracker (history, lost
  detection, click interval)
- WifiService: scan results carry BSSID, channel and security; a scan
  can target one channel for quick tracker refreshes; endListScans()
  turns the radio back off when Wi-Fi is disabled
- Wi-Fi Tools App: networks nearby, channel occupancy bars, signal
  tracker with clicks (m to mute)
- M1 plan: Monitoring-mode views and captures deferred

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

src/apps/wifi_tools_app.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "app.h"
+#include "list_model.h"
+#include "services/wifi_service.h"
+#include "signal_tracker.h"
+#include "ui/theme.h"
+
+namespace roro {
+
+// Wi-Fi diagnostics from ordinary scans: nearby access points, how crowded each channel is, and
+// a signal tracker for finding one access point. None of it interrupts the connection or IRC.
+class WifiToolsApp : public App {
+   public:
+    explicit WifiToolsApp(WifiService& wifi) : wifi_(wifi) {}
+    void onEnter() override;
+    void onExit() override;
+    bool onKey(const KeyEvent& e) override;
+    void update(uint32_t nowMs) override;
+    void draw(Canvas& c) override;
+
+   private:
+    enum class View { Menu, Networks, Channels, Tracker };
+
+    void open(View v);
+    void drawNetworks(Canvas& c);
+    void drawChannels(Canvas& c);
+    void drawTracker(Canvas& c);
+    std::vector<ScanEntry> sortedScan() const;
+
+    WifiService& wifi_;
+    View view_ = View::Menu;
+    ListModel menu_{theme::kContent.h / theme::kLineHeight};
+    ListModel networks_{theme::kContent.h / theme::kLineHeight};
+    uint32_t seenSeq_ = 0;
+    uint32_t nextScanMs_ = 0;
+
+    // Tracker
+    std::string targetBssid_, targetName_;
+    int targetChannel_ = 0;
+    SignalTracker tracker_{110};
+    bool clicks_ = true;
+    uint32_t nextClickMs_ = 0;
+};
+
+}  // namespace roro