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.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include <cstdint>
+#include <string>
+#include <vector>
+
+#include "scan_entry.h"
+
+namespace roro {
+
+// Writes what Wi-Fi Tools already sees (access points, channel, signal) to a CSV Log, so the user
+// can track their own Wi-Fi environment over time. One row per access point per logged scan.
+namespace scanlog {
+
+// A CSV field, quoted when it contains a comma, quote or newline.
+std::string csvField(const std::string& value);
+
+// The header row (no trailing newline).
+std::string header();
+
+// One data row for an access point seen at `timestamp` (a preformatted local time string).
+std::string row(const std::string& timestamp, const ScanEntry& ap);
+
+}  // namespace scanlog
+
+// Decides when to write a scan to the Log: at most once per interval.
+class ScanLogThrottle {
+   public:
+    explicit ScanLogThrottle(uint32_t intervalMs) : intervalMs_(intervalMs) {}
+    bool due(uint32_t nowMs) const { return !logged_ || nowMs - lastMs_ >= intervalMs_; }
+    void logged(uint32_t nowMs) {
+        lastMs_ = nowMs;
+        logged_ = true;
+    }
+    void reset() { logged_ = false; }
+
+   private:
+    uint32_t intervalMs_;
+    uint32_t lastMs_ = 0;
+    bool logged_ = false;
+};
+
+}  // namespace roro