M3 step 4: the LoRa Scanner App, Sniffer and Captures

The Sniffer lists packets newest first (time, RSSI, SNR, and for
Meshtastic the sender, receiver and hops), with the clear header and a
hex dump on Enter (Q96); `p` picks an EU868 preset, kept in Settings
(Q95). `c` starts a Capture: pcap with LoRaTap in /captures/lora, its own
Clean-up category, recorded by a small Service so it carries on with the
App closed (Q97, Q100). The Status Bar shows L while listening, bright on
each packet, and CAP while capturing (Q101). StorageService gains raw
appends for binary files. Debug Builds get `lora inject` to test all of
this with no transmitter in range: a Capture made on the device reads
back in TShark field for field.

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

test/test_loratap/test_loratap.cpp

@@ -83,11 +83,16 @@ void test_rssi_clamped() {
     TEST_ASSERT_EQUAL_UINT8(159, out[16 + 12]);
 }
 
+void test_capture_path() {
+    TEST_ASSERT_EQUAL_STRING("/captures/lora/20261005-200000.pcap", capturePath(1791230400).c_str());
+}
+
 int main() {
     UNITY_BEGIN();
     RUN_TEST(test_pcap_global_header);
     RUN_TEST(test_record_with_loratap_v0);
     RUN_TEST(test_negative_snr);
     RUN_TEST(test_rssi_clamped);
+    RUN_TEST(test_capture_path);
     return UNITY_END();
 }