-- Soft-delete (admin moderation) for posts and comments. Additive: the column
-- is nullable and defaults to NULL, and every read query now filters
-- `deleted_at IS NULL` — a no-op for existing rows (all NULL), so nothing in
-- the live app changes until an admin actually deletes something. A soft-
-- deleted row disappears from all reads but stays in the table, recoverable
-- via the admin "restore" action.
ALTER TABLE posts
    ADD COLUMN IF NOT EXISTS deleted_at TIMESTAMPTZ;

ALTER TABLE post_comments
    ADD COLUMN IF NOT EXISTS deleted_at TIMESTAMPTZ;

-- Partial indexes keep the hot "not deleted" reads fast (they match the
-- deleted_at IS NULL predicate now on every posts/comments query).
CREATE INDEX IF NOT EXISTS posts_not_deleted_idx
    ON posts (created_at DESC) WHERE deleted_at IS NULL;
CREATE INDEX IF NOT EXISTS post_comments_not_deleted_idx
    ON post_comments (post_id) WHERE deleted_at IS NULL;