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/tester/source.go

@@ -0,0 +1,50 @@
+package tester
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/AlexxIT/go2rtc/pkg/core"
+	"github.com/AlexxIT/go2rtc/pkg/rtsp"
+)
+
+// SourceHandler tests stream URL, returns Producer or error
+type SourceHandler func(rawURL string) (core.Producer, error)
+
+var handlers = map[string]SourceHandler{}
+
+func RegisterSource(scheme string, handler SourceHandler) {
+	handlers[scheme] = handler
+}
+
+func GetHandler(rawURL string) SourceHandler {
+	if i := strings.IndexByte(rawURL, ':'); i > 0 {
+		return handlers[rawURL[:i]]
+	}
+	return nil
+}
+
+func init() {
+	RegisterSource("rtsp", rtspHandler)
+	RegisterSource("rtsps", rtspHandler)
+	RegisterSource("rtspx", rtspHandler)
+}
+
+// rtspHandler -- Dial + Describe. Proves: port open, RTSP responds, auth OK, SDP received.
+func rtspHandler(rawURL string) (core.Producer, error) {
+	rawURL, _, _ = strings.Cut(rawURL, "#")
+
+	conn := rtsp.NewClient(rawURL)
+	conn.Backchannel = false
+
+	if err := conn.Dial(); err != nil {
+		return nil, fmt.Errorf("rtsp: dial: %w", err)
+	}
+
+	if err := conn.Describe(); err != nil {
+		_ = conn.Stop()
+		return nil, fmt.Errorf("rtsp: describe: %w", err)
+	}
+
+	return conn, nil
+}