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_log.cpp

@@ -0,0 +1,27 @@
+#include "scan_log.h"
+
+namespace roro::scanlog {
+
+std::string csvField(const std::string& value) {
+    bool needsQuote = false;
+    for (char c : value)
+        if (c == ',' || c == '"' || c == '\n' || c == '\r') needsQuote = true;
+    if (!needsQuote) return value;
+    std::string out = "\"";
+    for (char c : value) {
+        if (c == '"') out += '"';  // escape by doubling
+        out += c;
+    }
+    out += '"';
+    return out;
+}
+
+std::string header() { return "time,bssid,channel,rssi,security,ssid"; }
+
+std::string row(const std::string& timestamp, const ScanEntry& ap) {
+    return csvField(timestamp) + "," + csvField(ap.bssid) + "," + std::to_string(ap.channel) + "," +
+           std::to_string(ap.rssi) + "," + csvField(ap.security) + "," +
+           csvField(ap.ssid.empty() ? "(hidden)" : ap.ssid);
+}
+
+}  // namespace roro::scanlog