fix(growth): HIGH-6 修复 extract_combined 合并提取空壳

根因: growth.rs 构造 CombinedExtraction 时硬编码 experiences: Vec::new()
和 profile_signals: default()，导致 L1 结构化经验不被提取、L2 技能进化
没有输入数据、整个进化引擎无法端到端工作。

修复:
- extractor.rs: 添加 COMBINED_EXTRACTION_PROMPT 统一 prompt，单次 LLM 调用
  同时输出 memories + experiences + profile_signals
- extractor.rs: 添加 parse_combined_response() 解析 LLM JSON 响应
- LlmDriverForExtraction trait: 添加 extract_with_prompt() 方法（默认不支持，
  退化到现有 extract() + 启发式推断）
- MemoryExtractor: 添加 extract_combined() 方法，优先单次调用，失败则退化
- growth.rs: extract_combined() 使用新的合并提取替代硬编码空值
- TauriExtractionDriver: 实现 extract_with_prompt()
- ProfileSignals: 添加 has_any_signal() 方法
- types.rs: ProfileSignals 无 structural 变化（字段已存在）

测试: 4 个新测试（parse_combined_response_full/minimal/invalid +
extract_combined_fallback），11 个 extractor 测试全部通过

desktop/src-tauri/src/intelligence/extraction_adapter.rs

@@ -225,6 +225,69 @@ impl LlmDriverForExtraction for TauriExtractionDriver {
 
         Ok(memories)
     }
+
+    async fn extract_with_prompt(
+        &self,
+        messages: &[Message],
+        system_prompt: &str,
+        user_prompt: &str,
+    ) -> Result<String> {
+        if messages.len() < 2 {
+            return Err(zclaw_types::Error::msg(
+                "Too few messages for combined extraction",
+            ));
+        }
+
+        tracing::debug!(
+            "[TauriExtractionDriver] Combined extraction from {} messages",
+            messages.len()
+        );
+
+        let request = CompletionRequest {
+            model: self.model.clone(),
+            system: Some(system_prompt.to_string()),
+            messages: vec![Message::user(user_prompt.to_string())],
+            tools: Vec::new(),
+            max_tokens: Some(3000),
+            temperature: Some(0.3),
+            stop: Vec::new(),
+            stream: false,
+            thinking_enabled: false,
+            reasoning_effort: None,
+            plan_mode: false,
+        };
+
+        let response = self.driver.complete(request).await.map_err(|e| {
+            tracing::error!(
+                "[TauriExtractionDriver] Combined extraction LLM call failed: {}",
+                e
+            );
+            e
+        })?;
+
+        let response_text: String = response
+            .content
+            .into_iter()
+            .filter_map(|block| match block {
+                ContentBlock::Text { text } => Some(text),
+                _ => None,
+            })
+            .collect::<Vec<_>>()
+            .join("");
+
+        if response_text.is_empty() {
+            return Err(zclaw_types::Error::msg(
+                "Empty response from LLM for combined extraction",
+            ));
+        }
+
+        tracing::info!(
+            "[TauriExtractionDriver] Combined extraction response: {} chars",
+            response_text.len()
+        );
+
+        Ok(response_text)
+    }
 }
 
 /// Global extraction driver instance (legacy path, kept for compatibility).