video settings: hide music API Configuration, add video API placeholders

On the video side the API Configuration section (Spotify/Tidal/Deezer/etc.) is
all music — hidden now (group marked data-music-only). In its place, a video API
Configuration group (data-video-only) with disabled TMDB + TVDB placeholders for
the metadata sources we'll likely use. Music side unchanged.

tests/test_video_side_shell.py

@@ -207,6 +207,13 @@ def test_video_library_mapping_ui_present_and_video_only():
     assert 'body[data-side="video"] #plex-library-selector-container' in css
 
 
+def test_video_side_hides_music_api_config_and_shows_placeholders():
+    css = _CSS_PATH.read_text(encoding="utf-8")
+    assert 'body[data-side="video"] [data-music-only]' in css   # music API hidden on video
+    assert "data-music-only" in _INDEX                          # the music API group is marked
+    assert "TMDB API Key" in _INDEX and "TVDB API Key" in _INDEX  # video placeholders
+
+
 def test_video_settings_module_referenced_and_isolated():
     assert "video/video-settings.js" in _INDEX
     stripped = _VSETTINGS_JS.strip()

webui/index.html

@@ -4288,7 +4288,7 @@
                         <!-- Left Column - API Configuration -->
                         <div class="settings-left-column">
                             <!-- API Configuration -->
-                            <div class="settings-group" data-stg="connections">
+                            <div class="settings-group" data-stg="connections" data-music-only>
                                 <h3>API Configuration <button class="stg-accordion-toggle" onclick="toggleAllServiceAccordions(this)">Expand All</button></h3>
 
                                 <!-- Metadata Source Selection (first — tells user what they're configuring for) -->
@@ -4739,6 +4739,22 @@
                                 </div>
                             </div>
 
+                            <!-- Video API Configuration (placeholders; shown only on the video
+                                 side in place of the music API services). -->
+                            <div class="settings-group" data-stg="connections" data-video-only>
+                                <h3>API Configuration</h3>
+                                <div class="form-group">
+                                    <label>TMDB API Key</label>
+                                    <input type="text" placeholder="The Movie Database — movie &amp; TV metadata" disabled>
+                                    <small style="color: #999; font-size: 0.9em; display: block; margin-top: 5px;">Coming soon — primary movie/TV metadata source.</small>
+                                </div>
+                                <div class="form-group">
+                                    <label>TVDB API Key</label>
+                                    <input type="text" placeholder="TheTVDB — TV series metadata" disabled>
+                                    <small style="color: #999; font-size: 0.9em; display: block; margin-top: 5px;">Coming soon — TV metadata source.</small>
+                                </div>
+                            </div>
+
                             <!-- Server Connections -->
                             <div class="settings-group" data-stg="connections">
                                 <h3>Server Connections</h3>

webui/static/video/video-side.css

@@ -129,6 +129,11 @@ body[data-side="video"] #jellyfin-library-selector-container,
 body[data-side="video"] #navidrome-folder-selector-container {
     display: none !important;
 }
+/* Music-only settings sections (e.g. the music API services) are hidden on the
+   video side; their video counterparts carry data-video-only. */
+body[data-side="video"] [data-music-only] {
+    display: none !important;
+}
 
 /* ── Dashboard header: match music, minus the sweep animation ──────────── */
 /* The header reuses music's .dashboard-header markup/CSS for an identical look;