feat: add API token authentication

internal/database/migrations/019_add_api_tokens.sql

@@ -0,0 +1,15 @@
+-- +goose Up
+CREATE TABLE IF NOT EXISTS api_token (
+    id TEXT PRIMARY KEY,
+    user_id TEXT NOT NULL REFERENCES user(id) ON DELETE CASCADE,
+    token_hash TEXT NOT NULL UNIQUE,
+    name TEXT NOT NULL,
+    created_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    last_used_at DATETIME,
+    revoked_at DATETIME
+);
+
+CREATE INDEX IF NOT EXISTS idx_api_token_user_id ON api_token(user_id);
+
+-- +goose Down
+DROP TABLE IF EXISTS api_token;