Rewrite Strix from scratch as single binary

Complete architecture rewrite following go2rtc patterns:
- pkg/ for pure logic (camdb, tester, probe, generate)
- internal/ for application glue with Init() modules
- Single HTTP server on :4567 with all endpoints
- zerolog with password masking and memory ring buffer
- Environment-based config only (no YAML files)

API endpoints: /api/search, /api/streams, /api/test,
/api/probe, /api/generate, /api/health, /api/log

Dependencies: go2rtc v1.9.14, go-sqlite3, miekg/dns, zerolog

pkg/probe/oui.go

@@ -0,0 +1,21 @@
+package probe
+
+import (
+	"database/sql"
+	"strings"
+)
+
+// LookupOUI returns vendor name for MAC address from SQLite oui table.
+// MAC format: "C0:56:E3:AA:BB:CC" -> prefix "C0:56:E3"
+func LookupOUI(db *sql.DB, mac string) string {
+	if len(mac) < 8 {
+		return ""
+	}
+
+	prefix := strings.ToUpper(mac[:8])
+	prefix = strings.ReplaceAll(prefix, "-", ":")
+
+	var brand string
+	_ = db.QueryRow("SELECT brand FROM oui WHERE prefix = ?", prefix).Scan(&brand)
+	return brand
+}