M0: scaffold SPA + API monorepo

Backend (Django 6.1 + DRF):
- Token auth with a custom User model (register/login/logout/me)
- Library models (MediaItem, MediaLocation) and REST endpoints
- File list/detail with search, rating filter, sorting, pagination
- Multipart upload with optional rating/tags/notes
- Range-aware media serving (video seeking) and ffmpeg thumbnails
- scan_files management command for the watched folder

Frontend (React 19 + Vite + TypeScript):
- Catppuccin Mocha design tokens from the design docs
- App shell, token persistence, protected routes
- Library grid with filters, file detail with custom data editor
- Upload page with per-file progress via XHR
- Dev proxy to the Django API

backend/apps/library/models.py

@@ -0,0 +1,38 @@
+from django.db import models
+
+
+class MediaItem(models.Model):
+    """A logical media file, identified by its MD5 fingerprint."""
+
+    md5 = models.CharField(max_length=32, unique=True)
+    size = models.BigIntegerField(default=0)
+    # Custom rating: "s" (safe), "q" (questionable), "e" (explicit) or "" (unrated).
+    rating = models.CharField(max_length=1, blank=True, default="")
+    tags = models.JSONField(default=list, blank=True)
+    notes = models.TextField(blank=True, default="")
+    created_at = models.DateTimeField(auto_now_add=True)
+    updated_at = models.DateTimeField(auto_now=True)
+
+    class Meta:
+        ordering = ["-created_at"]
+
+    def __str__(self):
+        return self.md5
+
+
+class MediaLocation(models.Model):
+    """A physical copy of a media item inside the watched folder."""
+
+    item = models.ForeignKey(
+        MediaItem, related_name="locations", on_delete=models.CASCADE
+    )
+    path = models.CharField(max_length=1024)
+    rel_path = models.CharField(max_length=1024)
+    mtime = models.FloatField(default=0)
+
+    class Meta:
+        unique_together = ("item", "path")
+        ordering = ["rel_path"]
+
+    def __str__(self):
+        return self.rel_path