release(secrets-mcp): 0.5.6

修复 OAuth 解绑时非法聚合 FOR UPDATE，Web OAuth 审计 IP 与 TRUST_PROXY 对齐并校验 IP，账号绑定写入 oauth_state 失败时回滚 bind 标记。回滚条目时恢复 folder/type，导入冲突检查在 DB 失败时传播错误，MCP delete/history 要求已登录用户，全局请求体 10MiB 限制。CI 部署支持 DEPLOY_KNOWN_HOSTS，默认 accept-new；文档与 deploy 示例补充连接池、限流、TRUST_PROXY。移除含明文凭据的 sync-test-to-prod 脚本。

crates/secrets-core/src/service/user.rs

@@ -200,10 +200,14 @@ pub async fn unbind_oauth_account(
         );
     }
 
-    let count: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM oauth_accounts WHERE user_id = $1")
-        .bind(user_id)
-        .fetch_one(pool)
-        .await?;
+    let mut tx = pool.begin().await?;
+
+    let locked_accounts: Vec<(String,)> =
+        sqlx::query_as("SELECT provider FROM oauth_accounts WHERE user_id = $1 FOR UPDATE")
+            .bind(user_id)
+            .fetch_all(&mut *tx)
+            .await?;
+    let count = locked_accounts.len();
 
     if count <= 1 {
         anyhow::bail!("Cannot unbind the last OAuth account. Please link another account first.");
@@ -212,8 +216,87 @@ pub async fn unbind_oauth_account(
     sqlx::query("DELETE FROM oauth_accounts WHERE user_id = $1 AND provider = $2")
         .bind(user_id)
         .bind(provider)
-        .execute(pool)
+        .execute(&mut *tx)
         .await?;
 
+    tx.commit().await?;
+
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    async fn maybe_test_pool() -> Option<PgPool> {
+        let database_url = match std::env::var("SECRETS_DATABASE_URL") {
+            Ok(v) => v,
+            Err(_) => {
+                eprintln!("skip user service tests: SECRETS_DATABASE_URL not set");
+                return None;
+            }
+        };
+        let pool = match sqlx::PgPool::connect(&database_url).await {
+            Ok(pool) => pool,
+            Err(e) => {
+                eprintln!("skip user service tests: cannot connect to database: {e}");
+                return None;
+            }
+        };
+        if let Err(e) = crate::db::migrate(&pool).await {
+            eprintln!("skip user service tests: migrate failed: {e}");
+            return None;
+        }
+        Some(pool)
+    }
+
+    async fn cleanup_user_rows(pool: &PgPool, user_id: Uuid) -> Result<()> {
+        sqlx::query("DELETE FROM oauth_accounts WHERE user_id = $1")
+            .bind(user_id)
+            .execute(pool)
+            .await?;
+        sqlx::query("DELETE FROM users WHERE id = $1")
+            .bind(user_id)
+            .execute(pool)
+            .await?;
+        Ok(())
+    }
+
+    #[tokio::test]
+    async fn unbind_oauth_account_removes_only_requested_provider() -> Result<()> {
+        let Some(pool) = maybe_test_pool().await else {
+            return Ok(());
+        };
+        let user_id = Uuid::from_u128(rand::random());
+
+        cleanup_user_rows(&pool, user_id).await?;
+
+        sqlx::query("INSERT INTO users (id, name) VALUES ($1, '')")
+            .bind(user_id)
+            .execute(&pool)
+            .await?;
+        sqlx::query(
+            "INSERT INTO oauth_accounts (user_id, provider, provider_id, email, name, avatar_url) \
+             VALUES ($1, 'google', $2, NULL, NULL, NULL), \
+                    ($1, 'github', $3, NULL, NULL, NULL)",
+        )
+        .bind(user_id)
+        .bind(format!("google-{user_id}"))
+        .bind(format!("github-{user_id}"))
+        .execute(&pool)
+        .await?;
+
+        unbind_oauth_account(&pool, user_id, "github", Some("google")).await?;
+
+        let remaining: Vec<(String,)> = sqlx::query_as(
+            "SELECT provider FROM oauth_accounts WHERE user_id = $1 ORDER BY provider",
+        )
+        .bind(user_id)
+        .fetch_all(&pool)
+        .await?;
+        assert_eq!(remaining, vec![("google".to_string(),)]);
+
+        cleanup_user_rows(&pool, user_id).await?;
+        Ok(())
+    }
+}