add d1kt SSO integration: OAuth2 login via WebView + phone binding

sentence_api/repository.py

@@ -156,6 +156,10 @@ class VideoRepository:
             }
             if "phone" not in user_columns:
                 connection.execute("ALTER TABLE users ADD COLUMN phone TEXT")
+            if "sso_provider" not in user_columns:
+                connection.execute("ALTER TABLE users ADD COLUMN sso_provider TEXT")
+            if "phone_bound" not in user_columns:
+                connection.execute("ALTER TABLE users ADD COLUMN phone_bound INTEGER NOT NULL DEFAULT 0")
             connection.execute("CREATE INDEX IF NOT EXISTS idx_attempts_user ON attempts(user_id)")
 
         with self._connect() as connection:
@@ -789,6 +793,43 @@ class VideoRepository:
             return None
         return self.get_user_by_id(user_id)
 
+    def create_sso_user(
+        self,
+        *,
+        username: str,
+        nickname: str,
+        email: str = "",
+        sso_provider: str = "d1kt",
+    ) -> Optional[Dict[str, Any]]:
+        user_id = uuid.uuid4().hex
+        now = utc_now()
+        try:
+            with self._connect() as connection:
+                connection.execute(
+                    """
+                    INSERT INTO users (id, username, nickname, phone, sso_provider, phone_bound, password_hash, created_at)
+                    VALUES (?, ?, ?, NULL, ?, 0, '', ?)
+                    """,
+                    (
+                        user_id,
+                        username.strip().lower(),
+                        (nickname or username).strip()[:80],
+                        sso_provider,
+                        now,
+                    ),
+                )
+        except sqlite3.IntegrityError:
+            return None
+        return self.get_user_by_id(user_id)
+
+    def bind_phone(self, user_id: str, phone: str) -> Optional[Dict[str, Any]]:
+        with self._connect() as connection:
+            connection.execute(
+                "UPDATE users SET phone = ?, phone_bound = 1 WHERE id = ?",
+                (phone.strip()[:20], user_id),
+            )
+        return self.get_user_by_id(user_id)
+
     def get_user_by_username(self, username: str) -> Optional[Dict[str, Any]]:
         with self._connect() as connection:
             row = connection.execute(