Replace emoji icons with local SVG files for consistent rendering

- Created 10 SVG icon files in app/static/icons/ (Feather Icons style)
- Updated base.html with SVG icons in navigation and dark mode toggle
- Updated dashboard.html with icons in stats cards and quick actions
- Updated content_list_new.html (playlist management) with SVG icons
- Updated upload_media.html with upload-related icons
- Updated manage_player.html with player management icons
- Icons use currentColor for automatic theme adaptation
- Removed emoji dependency for better Raspberry Pi compatibility
- Added ICON_INTEGRATION.md documentation

app/models/playlist.py

@@ -0,0 +1,97 @@
+"""Playlist model for managing content collections."""
+from datetime import datetime
+from typing import List, Optional
+
+from app.extensions import db
+
+
+# Association table for many-to-many relationship between playlists and content
+playlist_content = db.Table('playlist_content',
+    db.Column('playlist_id', db.Integer, db.ForeignKey('playlist.id', ondelete='CASCADE'), primary_key=True),
+    db.Column('content_id', db.Integer, db.ForeignKey('content.id', ondelete='CASCADE'), primary_key=True),
+    db.Column('position', db.Integer, default=0),
+    db.Column('duration', db.Integer, default=10)
+)
+
+
+class Playlist(db.Model):
+    """Playlist model representing a collection of content.
+    
+    Attributes:
+        id: Primary key
+        name: Unique playlist name
+        description: Optional playlist description
+        version: Version number for synchronization
+        is_active: Whether playlist is active
+        created_at: Playlist creation timestamp
+        updated_at: Last modification timestamp
+    """
+    __tablename__ = 'playlist'
+    
+    id = db.Column(db.Integer, primary_key=True)
+    name = db.Column(db.String(100), nullable=False, unique=True, index=True)
+    description = db.Column(db.Text, nullable=True)
+    orientation = db.Column(db.String(20), default='Landscape', nullable=False)
+    version = db.Column(db.Integer, default=1, nullable=False)
+    is_active = db.Column(db.Boolean, default=True, nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
+    updated_at = db.Column(db.DateTime, default=datetime.utcnow, 
+                          onupdate=datetime.utcnow, nullable=False)
+    
+    # Relationships
+    players = db.relationship('Player', back_populates='playlist', lazy='dynamic')
+    contents = db.relationship('Content', secondary=playlist_content, 
+                              back_populates='playlists', lazy='dynamic')
+    
+    def __repr__(self) -> str:
+        """String representation of Playlist."""
+        return f'<Playlist {self.name} (ID={self.id}, Version={self.version})>'
+    
+    @property
+    def player_count(self) -> int:
+        """Get number of players assigned to this playlist."""
+        return self.players.count()
+    
+    @property
+    def content_count(self) -> int:
+        """Get number of content items in this playlist."""
+        return self.contents.count()
+    
+    @property
+    def total_duration(self) -> int:
+        """Calculate total duration of all content in seconds."""
+        total = 0
+        for content in self.contents:
+            total += content.duration or 10
+        return total
+    
+    def increment_version(self) -> None:
+        """Increment playlist version for sync detection."""
+        self.version += 1
+        self.updated_at = datetime.utcnow()
+    
+    def get_content_ordered(self) -> List:
+        """Get content items ordered by position."""
+        # Query through association table to get position
+        from sqlalchemy import select
+        stmt = select(playlist_content.c.content_id, 
+                     playlist_content.c.position,
+                     playlist_content.c.duration).where(
+            playlist_content.c.playlist_id == self.id
+        ).order_by(playlist_content.c.position)
+        
+        results = db.session.execute(stmt).fetchall()
+        
+        ordered_content = []
+        for row in results:
+            content = db.session.get(Content, row.content_id)
+            if content:
+                content._playlist_position = row.position
+                content._playlist_duration = row.duration
+                ordered_content.append(content)
+        
+        return ordered_content
+
+
+# Import Content here to avoid circular import
+from app.models.content import Content