Wi-Fi Tools: scan logging to CSV, plus sort and filter

- lib/wifi (host-tested): scan_log (CSV field quoting, header/row, a
  once-per-interval throttle) and network_list_view (sort by signal /
  channel / name, filter open-only / hide-hidden / strong-only)
- ScanEntry moved to lib/wifi so both are testable on the PC
- Wi-Fi Tools networks view: s sort, o/h/w filters, l toggles logging
  to /wifi/scans/<date>.csv (header + one row per AP per logged scan,
  throttled 30 s, needs the clock for timestamps); foreground-only
- Wi-Fi scan logs replace probe-request logs as a clean-up category
- Serial: cat <path>, and key <char> injects a character

Verified on the device: CSV written with header, timestamps, BSSID,
channel, RSSI, security and SSID; hidden networks marked.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

lib/wifi/src/scan_entry.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include <string>
+
+namespace roro {
+
+// One access point an ordinary Wi-Fi scan reported (a network announcing itself). No client or
+// monitor-mode data: just what a beacon broadcasts.
+struct ScanEntry {
+    std::string ssid;   // empty for a hidden network
+    std::string bssid;  // the access point's own address, from its beacon
+    int channel;
+    int rssi;
+    bool open;
+    std::string security;  // "open", "WPA2", "WPA3"...
+};
+
+}  // namespace roro