Add header quick links with CRUD management and icon enhancements

- Add LinkConfig model and links field to settings
- Add CRUD API endpoints for links (list/create/update/delete)
- Add Links management tab in WebUI with add/edit/delete dialogs
- Add live icon preview in Link and Script dialog forms
- Show MDI icons inline in Quick Actions cards, Scripts table, Links table
- Add broadcast_links_changed WebSocket event for live updates
- Add EN/RU translations for all links management strings

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

media_server/config.py

@@ -39,6 +39,14 @@ class ScriptConfig(BaseModel):
     shell: bool = Field(default=True, description="Run command in shell")
 
 
+class LinkConfig(BaseModel):
+    """Configuration for a header quick link."""
+
+    url: str = Field(..., description="URL to open")
+    icon: str = Field(default="mdi:link", description="MDI icon name (e.g., 'mdi:led-strip-variant')")
+    label: str = Field(default="", description="Tooltip text")
+
+
 class Settings(BaseSettings):
     """Application settings loaded from environment or config file."""
 
@@ -97,6 +105,12 @@ class Settings(BaseSettings):
         description='Thumbnail size: "small" (150x150), "medium" (300x300), or "both"',
     )
 
+    # Header quick links
+    links: dict[str, LinkConfig] = Field(
+        default_factory=dict,
+        description="Quick links displayed as icons in the header",
+    )
+
     @classmethod
     def load_from_yaml(cls, path: Optional[Path] = None) -> "Settings":
         """Load settings from a YAML configuration file."""