fix: 修复 anthropic 煞笔的四个 bug (#352)

* fix: 移除文件编辑前必须先读取的限制

移除 FileEditTool 和 FileWriteTool 中的 "read before edit" 校验，
允许直接编辑未读取过的文件。保留文件修改过期检测。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* docs: 更新 teach-me 自动写 note 笔记的功能

* fix: 修复 DeepSeek V4 reasoning_content 回传导致的 400 错误

- 扩大模型名称检测范围，匹配所有 deepseek 模型（V4、R1 等）
- 始终保留 thinking blocks 为 reasoning_content 回传给 API
- 移除有 bug 的 turn boundary 剥离逻辑

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: Opus 4.6/4.7 默认推理 effort 从 medium 改为 high

Pro 和 Max/Team 订阅者的 Opus 默认 effort 之前被降级为 medium，
导致用户感知模型「变笨」。恢复为 high。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: 移除 thinkingClearLatched sticky-on 机制

空闲超过 1 小时后 thinkingClearLatched 会被触发且永不重置，
导致每轮 API 调用都清除 thinking 历史。完整移除该 latch 机制，
clearAllThinking 硬编码为 false。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: 移除 numeric_length_anchors 系统指令

删除「工具调用间文字 ≤25 词、最终回复 ≤100 词」的硬性限制。
ablation 测试显示该约束使整体智能下降 3%。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

* fix: 修复测试中 reasoning_content 类型断言

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

src/constants/prompts.ts

@@ -614,17 +614,6 @@ ${CYBER_RISK_INSTRUCTION}`,
       'summarize_tool_results',
       () => SUMMARIZE_TOOL_RESULTS_SECTION,
     ),
-    // Numeric length anchors — research shows ~1.2% output token reduction vs
-    // qualitative "be concise". Ant-only to measure quality impact first.
-    ...(process.env.USER_TYPE === 'ant'
-      ? [
-          systemPromptSection(
-            'numeric_length_anchors',
-            () =>
-              'Length limits: keep text between tool calls to \u226425 words. Keep final responses to \u2264100 words unless the task requires more detail.',
-          ),
-        ]
-      : []),
     ...(feature('TOKEN_BUDGET')
       ? [
           // Cached unconditionally — the "When the user specifies..." phrasing