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/content.py

@@ -3,7 +3,6 @@ from datetime import datetime
 from typing import Optional, List
 
 from app.extensions import db
-from app.models.group import group_content
 
 
 class Content(db.Model):
@@ -13,31 +12,26 @@ class Content(db.Model):
         id: Primary key
         filename: Original filename
         content_type: Type of content (image, video, pdf, presentation, other)
-        duration: Display duration in seconds
+        duration: Default display duration in seconds
         file_size: File size in bytes
         description: Optional content description
-        position: Display order position
         uploaded_at: Upload timestamp
     """
     __tablename__ = 'content'
     
     id = db.Column(db.Integer, primary_key=True)
-    filename = db.Column(db.String(255), nullable=False, index=True)
+    filename = db.Column(db.String(255), nullable=False, unique=True, index=True)
     content_type = db.Column(db.String(50), nullable=False, index=True)
     duration = db.Column(db.Integer, default=10, nullable=True)
     file_size = db.Column(db.BigInteger, nullable=True)
     description = db.Column(db.Text, nullable=True)
-    position = db.Column(db.Integer, default=0, index=True)
     uploaded_at = db.Column(db.DateTime, default=datetime.utcnow, 
                            nullable=False, index=True)
     
-    # Player relationship (for direct player assignment)
-    player_id = db.Column(db.Integer, db.ForeignKey('player.id', ondelete='CASCADE'), 
-                         nullable=True, index=True)
-    
-    # Relationships
-    player = db.relationship('Player', back_populates='contents')
-    groups = db.relationship('Group', secondary=group_content, 
+    # Relationships - many-to-many with playlists
+    playlists = db.relationship('Playlist', secondary='playlist_content', 
+                               back_populates='contents', lazy='dynamic')
+    groups = db.relationship('Group', secondary='group_content', 
                             back_populates='contents', lazy='dynamic')
     
     def __repr__(self) -> str: