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/dns.go

@@ -0,0 +1,21 @@
+package probe
+
+import (
+	"context"
+	"net"
+	"strings"
+)
+
+func ReverseDNS(ctx context.Context, ip string) (*DNSResult, error) {
+	names, err := net.DefaultResolver.LookupAddr(ctx, ip)
+	if err != nil || len(names) == 0 {
+		return nil, nil
+	}
+
+	hostname := strings.TrimSuffix(names[0], ".")
+	if hostname == "" {
+		return nil, nil
+	}
+
+	return &DNSResult{Hostname: hostname}, nil
+}