implement post metadata import and views. implemented series paging and reader view.

app/models.py

@@ -101,6 +101,69 @@ class ImportBatch(db.Model):
     completed_at = db.Column(db.DateTime, nullable=True)
 
 
+class PostMetadata(db.Model):
+    """
+    Stores metadata about posts from external platforms (Patreon, SubscribeStar, HentaiFoundry).
+    Links to a Tag with kind='post' (format: post:platform:artist:id).
+    """
+    __tablename__ = "post_metadata"
+
+    id = db.Column(db.Integer, primary_key=True)
+
+    # Link to the post tag (post:platform:artist:id)
+    tag_id = db.Column(db.Integer, db.ForeignKey("tag.id", ondelete="CASCADE"), nullable=False, unique=True)
+    tag = db.relationship("Tag", backref=db.backref("post_metadata", uselist=False))
+
+    # Platform identification
+    platform = db.Column(db.String(64), nullable=False)  # patreon, subscribestar, hentaifoundry
+    post_id = db.Column(db.String(64), nullable=False)  # Original post ID on platform
+    artist = db.Column(db.String(255), nullable=True)
+
+    # Content
+    title = db.Column(db.String(512), nullable=True)
+    description = db.Column(db.Text, nullable=True)  # May contain HTML
+    source_url = db.Column(db.String(1024), nullable=True)  # Link to original post
+
+    # Statistics
+    attachment_count = db.Column(db.Integer, default=0)  # Number of images in post
+
+    # Timestamps
+    published_at = db.Column(db.DateTime, nullable=True)  # Original publish date
+    created_at = db.Column(db.DateTime, default=db.func.now())
+    updated_at = db.Column(db.DateTime, default=db.func.now(), onupdate=db.func.now())
+
+
+class SeriesPage(db.Model):
+    """
+    Links images to series tags with page numbers for ordered reading.
+    An image can only belong to one series at a time.
+    """
+    __tablename__ = "series_page"
+
+    id = db.Column(db.Integer, primary_key=True)
+
+    # Link to the series tag (must be kind='series')
+    series_tag_id = db.Column(db.Integer, db.ForeignKey("tag.id", ondelete="CASCADE"), nullable=False)
+    series_tag = db.relationship("Tag", backref=db.backref("series_pages", lazy="dynamic"))
+
+    # Link to the image (unique - image can only be in one series)
+    image_id = db.Column(db.Integer, db.ForeignKey("image_record.id", ondelete="CASCADE"), nullable=False, unique=True)
+    image = db.relationship("ImageRecord", backref=db.backref("series_page", uselist=False))
+
+    # Page number within the series
+    page_number = db.Column(db.Integer, nullable=False)
+
+    # Timestamps
+    created_at = db.Column(db.DateTime, default=db.func.now())
+    updated_at = db.Column(db.DateTime, default=db.func.now(), onupdate=db.func.now())
+
+    __table_args__ = (
+        # Each page number must be unique within a series
+        db.UniqueConstraint('series_tag_id', 'page_number', name='uq_series_page_number'),
+        db.Index('ix_series_page_series_tag', 'series_tag_id'),
+    )
+
+
 class ImportTask(db.Model):
     """
     Tracks the state of each file being processed through the import pipeline.