feat: expand MetalCircle app and privacy controls

db/init/01_initial.sql

@@ -40,6 +40,17 @@ CREATE TABLE friendships (
 CREATE UNIQUE INDEX idx_friendships_pair
     ON friendships (LEAST(requester_id, addressee_id), GREATEST(requester_id, addressee_id));
 
+CREATE TABLE user_blocks (
+    blocker_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    blocked_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    PRIMARY KEY (blocker_id, blocked_id),
+    CHECK (blocker_id <> blocked_id)
+);
+
+CREATE INDEX idx_user_blocks_blocked
+    ON user_blocks (blocked_id, blocker_id);
+
 CREATE TABLE direct_messages (
     id SERIAL PRIMARY KEY,
     sender_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,