Add go2rtc stream selection to camera configuration (#23496)

* add go2rtc stream selection to camera ffmpeg config

* i18n

* add config-schema.json to generated e2e mock data

* e2e test

* docs

* fix test

web/src/components/config-form/theme/fields/streamSource.ts

@@ -0,0 +1,33 @@
+export type StreamSourceMode = "restream" | "manual";
+
+// The literal go2rtc restream prefix matches what the camera wizard inlines
+// when it builds a restreamed input path. Only this exact host:port is treated
+// as a restream so manually typed URLs (including localhost) stay manual.
+export const RESTREAM_PREFIX = "rtsp://127.0.0.1:8554/";
+export const RESTREAM_PRESET = "preset-rtsp-restream";
+
+/** Build the restream input path for a given go2rtc stream name. */
+export function buildRestreamPath(streamName: string): string {
+  return `${RESTREAM_PREFIX}${streamName}`;
+}
+
+/**
+ * Extract the go2rtc stream name from a restream input path.
+ *
+ * Returns the stream name when the path is a well-formed restream URL with no
+ * extra path segments or query, otherwise undefined.
+ */
+export function parseRestreamStreamName(
+  path: string | undefined,
+): string | undefined {
+  if (typeof path !== "string" || !path.startsWith(RESTREAM_PREFIX)) {
+    return undefined;
+  }
+
+  const name = path.slice(RESTREAM_PREFIX.length);
+  if (name.length === 0 || /[/?#]/.test(name)) {
+    return undefined;
+  }
+
+  return name;
+}