[ie/youtube] Player client maintenance (#14135)

- Prioritize `tv_simply` over `tv` in default logged-out clients
- Revert `tv` client user-agent to work around 403 errors

Authored by: bashonly

README.md

@@ -1802,7 +1802,7 @@ The following extractors use this feature:
 #### youtube
 * `lang`: Prefer translated metadata (`title`, `description` etc) of this language code (case-sensitive). By default, the video primary language metadata is preferred, with a fallback to `en` translated. See [youtube/_base.py](https://github.com/yt-dlp/yt-dlp/blob/415b4c9f955b1a0391204bd24a7132590e7b3bdb/yt_dlp/extractor/youtube/_base.py#L402-L409) for the list of supported content language codes
 * `skip`: One or more of `hls`, `dash` or `translated_subs` to skip extraction of the m3u8 manifests, dash manifests and [auto-translated subtitles](https://github.com/yt-dlp/yt-dlp/issues/4090#issuecomment-1158102032) respectively
-* `player_client`: Clients to extract video data from. The currently available clients are `web`, `web_safari`, `web_embedded`, `web_music`, `web_creator`, `mweb`, `ios`, `android`, `android_vr`, `tv`, `tv_simply` and `tv_embedded`. By default, `tv,tv_simply,web` is used, but `tv,web_safari,web` is used when authenticating with cookies and `tv,web_creator,web` is used with premium accounts. The `web_music` client is added for `music.youtube.com` URLs when logged-in cookies are used. The `web_embedded` client is added for age-restricted videos but only works if the video is embeddable. The `tv_embedded` and `web_creator` clients are added for age-restricted videos if account age-verification is required. Some clients, such as `web` and `web_music`, require a `po_token` for their formats to be downloadable. Some clients, such as `web_creator`, will only work with authentication. Not all clients support authentication via cookies. You can use `default` for the default clients, or you can use `all` for all clients (not recommended). You can prefix a client with `-` to exclude it, e.g. `youtube:player_client=default,-ios`
+* `player_client`: Clients to extract video data from. The currently available clients are `web`, `web_safari`, `web_embedded`, `web_music`, `web_creator`, `mweb`, `ios`, `android`, `android_vr`, `tv`, `tv_simply` and `tv_embedded`. By default, `tv_simply,tv,web` is used, but `tv,web_safari,web` is used when authenticating with cookies and `tv,web_creator,web` is used with premium accounts. The `web_music` client is added for `music.youtube.com` URLs when logged-in cookies are used. The `web_embedded` client is added for age-restricted videos but only works if the video is embeddable. The `tv_embedded` and `web_creator` clients are added for age-restricted videos if account age-verification is required. Some clients, such as `web` and `web_music`, require a `po_token` for their formats to be downloadable. Some clients, such as `web_creator`, will only work with authentication. Not all clients support authentication via cookies. You can use `default` for the default clients, or you can use `all` for all clients (not recommended). You can prefix a client with `-` to exclude it, e.g. `youtube:player_client=default,-ios`
 * `player_skip`: Skip some network requests that are generally needed for robust extraction. One or more of `configs` (skip client configs), `webpage` (skip initial webpage), `js` (skip js player), `initial_data` (skip initial data/next ep request). While these options can help reduce the number of requests needed or avoid some rate-limiting, they could cause issues such as missing formats or metadata.  See [#860](https://github.com/yt-dlp/yt-dlp/pull/860) and [#12826](https://github.com/yt-dlp/yt-dlp/issues/12826) for more details
 * `webpage_skip`: Skip extraction of embedded webpage data. One or both of `player_response`, `initial_data`. These options are for testing purposes and don't skip any network requests
 * `player_params`: YouTube player parameters to use for player requests. Will overwrite any default ones set by yt-dlp.

yt_dlp/extractor/youtube/_base.py

@@ -305,8 +305,7 @@ INNERTUBE_CLIENTS = {
             'client': {
                 'clientName': 'TVHTML5',
                 'clientVersion': '7.20250312.16.00',
-                # See: https://github.com/youtube/cobalt/blob/main/cobalt/browser/user_agent/user_agent_platform_info.cc#L506
+                'userAgent': 'Mozilla/5.0 (ChromiumStylePlatform) Cobalt/Version',
-                'userAgent': 'Mozilla/5.0 (ChromiumStylePlatform) Cobalt/25.lts.30.1034943-gold (unlike Gecko), Unknown_TV_Unknown_0/Unknown (Unknown, Unknown)',
             },
         },
         'INNERTUBE_CONTEXT_CLIENT_NAME': 7,

yt_dlp/extractor/youtube/_video.py

@@ -257,7 +257,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
         '401': {'ext': 'mp4', 'height': 2160, 'format_note': 'DASH video', 'vcodec': 'av01.0.12M.08'},
     }
     _SUBTITLE_FORMATS = ('json3', 'srv1', 'srv2', 'srv3', 'ttml', 'srt', 'vtt')
-    _DEFAULT_CLIENTS = ('tv', 'tv_simply', 'web')
+    _DEFAULT_CLIENTS = ('tv_simply', 'tv', 'web')
     _DEFAULT_AUTHED_CLIENTS = ('tv', 'web_safari', 'web')
     # Premium does not require POT (except for subtitles)
     _DEFAULT_PREMIUM_CLIENTS = ('tv', 'web_creator', 'web')