Add social features and harden beta release

db/migrations/08_direct_messages.sql

@@ -0,0 +1,15 @@
+CREATE TABLE IF NOT EXISTS direct_messages (
+    id SERIAL PRIMARY KEY,
+    sender_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    recipient_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    body TEXT NOT NULL,
+    read_at TIMESTAMP,
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CHECK (sender_id <> recipient_id)
+);
+
+CREATE INDEX IF NOT EXISTS idx_direct_messages_conversation
+ON direct_messages (sender_id, recipient_id, created_at);
+
+CREATE INDEX IF NOT EXISTS idx_direct_messages_unread
+ON direct_messages (recipient_id, read_at);