重构: 后端 df-ai/commands 拆分+df-nodes/workflow 改造+P0 bug 修复

- df-ai: context 历史中毒三档自愈 sanitize_messages(AC3)+anthropic_compat tool_use_id None 跳过(AC1/AC2)+删 router/stream 死码
- df-core: events 加 select_type+decisions 多选审批契约(F-260615-01)
- df-execute: shell run_command 工具复用(F-260615-05)
- df-nodes: human_node 多选校验+2 端到端测(F-01)+取消跳 set_failed(B-03b-R1/R2/R8)
- df-workflow: executor/dag/state cancel 闭环(B-06/07/03a/b)+provider approve options(R-PD-5)
- df-storage: find_path_conflict 抽公共(R-PD-11)+COLS 常量断言
- df-ideas: 删 IdeaPromoter/PromotionPolicy 死码(R-PD-14)
- src-tauri/commands/ai: secret keyring 迁移(FR-S1/R-PD-4)+GeneratingGuard RAII+disarm(B-09/26)+newConversation 软复位(B-10)+stream 心跳/stop select/空回复判错(B-02/04/05/15)+run_command(F-05)+mask audit(AR-3)
- src-tauri/commands/{project,task,workflow,mod,lib,state}: task detail IPC(F-02)+approve decisions+task list 联动(B-29)
- Cargo.lock+Cargo.toml 依赖同步

crates/df-nodes/src/ai_node.rs

@@ -47,6 +47,10 @@ fn parse_params(
         .and_then(|v| v.as_str())
         .ok_or_else(|| anyhow::anyhow!("AiNode 缺少必填参数: api_key"))?
         .to_string();
+    // 空 key 早失败:避免空 key 发请求吃 401,错误伪装成"API Key 无效"(与 src-tauri secret::ensure_resolved_key 行为对齐)
+    if api_key.trim().is_empty() {
+        anyhow::bail!("AiNode api_key 为空(请检查节点配置或密钥注入链路),已阻止请求避免 401 误导");
+    }
 
     // ── prompt（必填）：优先取上游节点 "prompt" 输出，回退 config.prompt ──
     let prompt = inputs