Add GET /api/v1/probe endpoint for device inspection

Fast (~1-3s) endpoint that gathers network info about a device
before full stream discovery. Runs ping first, then parallel probes.

Features:
- Ping with ICMP + TCP fallback (works without root)
- Reverse DNS hostname lookup
- ARP table MAC address + OUI vendor identification (2403 entries, 51 camera vendors)
- mDNS HomeKit detection (camera/doorbell, paired status)
- Extensible Prober interface for adding new probe types
- 3-second overall timeout, parallel execution

Response includes "type" field:
- "unreachable" - device not responding
- "standard" - normal IP camera (RTSP/HTTP/ONVIF flow)
- "homekit" - Apple HomeKit camera (PIN pairing flow)

go.mod

@@ -5,6 +5,7 @@ go 1.24.0
 toolchain go1.24.9
 
 require (
+	github.com/AlexxIT/go2rtc v1.9.14
 	github.com/IOTechSystems/onvif v1.2.0
 	github.com/go-chi/chi/v5 v5.2.3
 	github.com/go-playground/validator/v10 v10.28.0
@@ -20,8 +21,20 @@ require (
 	github.com/go-playground/locales v0.14.1 // indirect
 	github.com/go-playground/universal-translator v0.18.1 // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/kr/text v0.2.0 // indirect
 	github.com/leodido/go-urn v1.4.0 // indirect
-	golang.org/x/crypto v0.42.0 // indirect
-	golang.org/x/sys v0.36.0 // indirect
-	golang.org/x/text v0.29.0 // indirect
+	github.com/miekg/dns v1.1.70 // indirect
+	github.com/pion/randutil v0.1.0 // indirect
+	github.com/pion/rtp v1.10.0 // indirect
+	github.com/pion/sdp/v3 v3.0.17 // indirect
+	github.com/rogpeppe/go-internal v1.14.1 // indirect
+	github.com/tadglines/go-pkgs v0.0.0-20210623144937-b983b20f54f9 // indirect
+	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/mod v0.32.0 // indirect
+	golang.org/x/net v0.49.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/sys v0.40.0 // indirect
+	golang.org/x/text v0.33.0 // indirect
+	golang.org/x/tools v0.41.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 )