feat: add user centric features

migrations/0006_create_posts.up.sql

@@ -0,0 +1,30 @@
+-- Posts are public quotes pulled from the knowledgebase. Each carries the
+-- selected text verbatim as its caption (immutable after create) plus a link
+-- back to the source URL the user was reading. Optional images are stored in
+-- the `post_images` table, one row per image, ordered by `position`.
+--
+-- Posts are always public — visibility is a per-user concern (the user's
+-- /u/<handle> feed), not a per-post one. Private saves should use bookmarks.
+CREATE TABLE IF NOT EXISTS posts (
+    id            UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id       UUID         NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    caption       TEXT         NOT NULL,
+    source_url    TEXT         NOT NULL,
+    source_title  VARCHAR(200),
+    created_at    TIMESTAMPTZ  NOT NULL DEFAULT now(),
+    updated_at    TIMESTAMPTZ  NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS posts_user_created_idx
+    ON posts (user_id, created_at DESC);
+
+CREATE TABLE IF NOT EXISTS post_images (
+    id          UUID         PRIMARY KEY DEFAULT gen_random_uuid(),
+    post_id     UUID         NOT NULL REFERENCES posts(id) ON DELETE CASCADE,
+    url         TEXT         NOT NULL,
+    position    INT          NOT NULL DEFAULT 0,
+    created_at  TIMESTAMPTZ  NOT NULL DEFAULT now()
+);
+
+CREATE INDEX IF NOT EXISTS post_images_post_idx
+    ON post_images (post_id, position);