修复: 协议层与体验缺陷六件

- temperature 按模型适配,仅收 1 的模型不再 400
- 流式 error 帧不再被 choices 必填整帧丢弃
- 只读缓存写后失效
- git diff 中文截断撞 UTF-8 边界 panic
- 非视觉模型纯图片直接拒绝
- 全局快捷键补输入焦点守卫

src-tauri/src/commands/ai/remote_bridge.rs

@@ -51,7 +51,7 @@
 
 use serde::Deserialize;
 use serde_json::Value;
-use tauri::{AppHandle, Emitter, State};
+use tauri::{AppHandle, State};
 
 use crate::state::AppState;
 

src-tauri/src/commands/ai/stream_recv.rs

@@ -102,6 +102,9 @@ pub(crate) enum StreamResult {
         usage: df_ai::provider::TokenUsage,
         /// DeepSeek thinking 模式推理内容（需回传到下一轮请求）
         reasoning_content: Option<String>,
+        /// 流因 provider max_tokens 上限截断(finish_reason=length / stop_reason=max_tokens)。
+        /// true=文本/tool_calls 可能不完整,调用方据此标记该轮产出截断,不冒充正常完成。
+        truncated_by_max_tokens: bool,
     },
     /// 流中途断（MidStream chunk Err / idle timeout / provider stream-error / 有 partial_text
     /// 但流尽未收到 finished）。已 emit 过 AiTextDelta（前端 currentText 已累积），
@@ -282,6 +285,9 @@ pub(crate) async fn stream_llm(
     let mut finished_received = false;
     let mut stopped = false;
     let mut final_usage: Option<df_ai::provider::TokenUsage> = None;
+    // max_tokens 截断标志跨帧 OR 累积(openai finish_reason=length / anthropic
+    // stop_reason=max_tokens 的帧先于终态帧到达),Complete 随旗标带出供上层标记截断。
+    let mut truncated_by_max_tokens = false;
     // DeepSeek thinking 模式推理内容累积（多轮需回传）
     let mut reasoning_content_acc: Option<String> = None;
     // per-conv delta 合批累加器。pending_delta 累积未 flush 的文本,
@@ -419,6 +425,9 @@ pub(crate) async fn stream_llm(
                         if let Some(u) = &chunk.usage {
                             final_usage = Some(u.clone());
                         }
+                        if chunk.truncated_by_max_tokens {
+                            truncated_by_max_tokens = true;
+                        }
                         if let Some(ref rc) = chunk.reasoning_content {
                             reasoning_content_acc.get_or_insert_with(String::new).push_str(rc);
                         }
@@ -540,6 +549,7 @@ pub(crate) async fn stream_llm(
             tool_calls: tool_calls_acc,
             usage: final_usage.unwrap_or_default(),
             reasoning_content: reasoning_content_acc,
+            truncated_by_max_tokens,
         };
     }
 
@@ -573,6 +583,7 @@ pub(crate) async fn stream_llm(
         tool_calls: tool_calls_acc,
         usage: final_usage.unwrap_or_default(),
         reasoning_content: reasoning_content_acc,
+        truncated_by_max_tokens,
     }
 }
 

src-tauri/src/commands/ai/tools/git.rs

@@ -156,9 +156,13 @@ async fn run_git_diff(working_dir: &str, staged: bool) -> serde_json::Value {
     let mut patch_args = vec!["diff"];
     if staged { patch_args.push("--cached"); }
     let patch_raw = exec_git_exit(working_dir, &patch_args).await.0;
-    // 截断到 8000 字符(防大体量 diff)
+    // 截断到 8000 字符(防大体量 diff);中文字节切片撞 UTF-8 边界会 panic,回退到字符边界
     let patch_truncated = if patch_raw.len() > 8000 {
-        format!("{}\n... (diff 截断,共 {} 字符)", &patch_raw[..8000], patch_raw.len())
+        let mut end = 8000;
+        while !patch_raw.is_char_boundary(end) {
+            end -= 1;
+        }
+        format!("{}\n... (diff 截断,共 {} 字符)", &patch_raw[..end], patch_raw.len())
     } else {
         patch_raw
     };