Initial commit: KeepItGoing task management server

Features:
- Django-based REST API with web interface
- Task management with tags, priorities, and due dates
- Time tracking with start/stop timers
- Subtasks support
- Task filtering (all, today, upcoming, overdue, completed)
- Tag-based organization with color coding
- Sorting by due date and priority
- Auto-assign tags when filtering
- Responsive 3-pane layout (sidebar, task list, detail panel)
- Task sharing between users
- Mobile-responsive design with dark mode support

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

sync/models.py

@@ -0,0 +1,65 @@
+"""
+Sync models for KeepItGoing.
+
+Tracks sync state for offline clients.
+"""
+
+import uuid
+from django.conf import settings
+from django.db import models
+
+
+class SyncLog(models.Model):
+    """
+    Tracks sync operations for each user/device.
+    """
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='sync_logs'
+    )
+    device_id = models.CharField(max_length=255)
+    last_sync_at = models.DateTimeField()
+    sync_token = models.CharField(max_length=255, unique=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = 'sync_logs'
+        unique_together = ['user', 'device_id']
+
+    def __str__(self):
+        return f"{self.user.email} - {self.device_id}"
+
+
+class SyncConflict(models.Model):
+    """
+    Records sync conflicts for manual resolution.
+    """
+    CONFLICT_STATUS = [
+        ('pending', 'Pending'),
+        ('resolved_local', 'Resolved (Local)'),
+        ('resolved_server', 'Resolved (Server)'),
+        ('resolved_merged', 'Resolved (Merged)'),
+    ]
+
+    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)
+    user = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name='sync_conflicts'
+    )
+    entity_type = models.CharField(max_length=50)  # task, group, tag, etc.
+    entity_id = models.UUIDField()
+    local_data = models.JSONField()
+    server_data = models.JSONField()
+    status = models.CharField(max_length=20, choices=CONFLICT_STATUS, default='pending')
+    resolved_at = models.DateTimeField(null=True, blank=True)
+    created_at = models.DateTimeField(auto_now_add=True)
+
+    class Meta:
+        db_table = 'sync_conflicts'
+        ordering = ['-created_at']
+
+    def __str__(self):
+        return f"{self.entity_type} conflict for {self.user.email}"