fix(system-config): re-read mediamtx.yml on each request (v0.6.2)

Configuration tab was showing stale yml because the file was parsed once at
startup and the result cached on Server. Now Parse runs per request so on-disk
edits — including our own UpsertPath writes — are visible immediately.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: nabaco

VERSION

@@ -1 +1 @@
-0.6.1
+0.6.2

internal/api/handlers_system.go

@@ -2,6 +2,8 @@ package api
 
 import (
 	"net/http"
+
+	"mediamtx-ui/internal/parser"
 )
 
 type systemInfoResponse struct {
@@ -40,14 +42,23 @@ func (s *Server) handleSystemInfo(w http.ResponseWriter, r *http.Request) {
 }
 
 func (s *Server) handleSystemConfig(w http.ResponseWriter, r *http.Request) {
-	if s.configFile == nil || !s.configFile.Available {
+	// Re-read on every request so edits (including ones we wrote via
+	// parser.UpsertPath) show up without a server restart. Falls back to
+	// the path the parser resolved at startup when no explicit ConfigPath
+	// is set in config.
+	path := s.cfg.MediaMTX.ConfigPath
+	if path == "" && s.configFile != nil {
+		path = s.configFile.ResolvedPath
+	}
+	cur := parser.Parse(path)
+	if cur == nil || !cur.Available {
 		jsonOK(w, systemConfigResponse{Available: false})
 		return
 	}
 	jsonOK(w, systemConfigResponse{
 		Available:    true,
-		ResolvedPath: s.configFile.ResolvedPath,
-		RawYAML:      s.configFile.RawYAML,
+		ResolvedPath: cur.ResolvedPath,
+		RawYAML:      cur.RawYAML,
 	})
 }