BEGIN;
ALTER TABLE posts ADD COLUMN edited_at timestamptz;
-- Code-authored Wiki pages retain their public IDs; saved edits outlive deployments.
CREATE TABLE note_edits (
 page_id text PRIMARY KEY CHECK(page_id ~ '^[0-9a-f]{24}$'),
 title text NOT NULL CHECK(length(btrim(title))>0), description text NOT NULL DEFAULT '',
 markdown text NOT NULL DEFAULT '', updated_at timestamptz NOT NULL DEFAULT now()
);
CREATE TABLE note_edit_tags (
 page_id text NOT NULL REFERENCES note_edits(page_id) ON DELETE CASCADE,
 tag_id uuid NOT NULL REFERENCES tags(id) ON DELETE RESTRICT,
 PRIMARY KEY(page_id,tag_id)
);
INSERT INTO schema_migrations(version) VALUES('005_note_editing');
COMMIT;