fix: 审计后续 3 项修复 — 残留清理 + FTS5 CJK + HTTP 大小限制

1. Shell Hands 残留清理 (3处):
   - message.rs: 移除过时的 zclaw_hands::slideshow 注释
   - user_profiler.rs: slideshow 偏好改为 RecentTopic
   - handStore.test.ts: 移除 speech mock 数据 (3→2)

2. zclaw-growth FTS5 CJK 查询修复:
   - sanitize_fts_query CJK 路径从精确短语改为 token OR 组合
   - "Rust 编程" → "rust" OR "编程" (之前是 "rust 编程" 精确匹配)
   - 修复 test_memory_lifecycle + test_semantic_search_ranking

3. WASM HTTP 响应大小限制:
   - Content-Length 预检 + 读取后截断 (1MB 上限)
   - read_to_string 改为显式错误处理

651 测试全通过，0 失败。

crates/zclaw-growth/src/storage/sqlite.rs

@@ -461,13 +461,58 @@ impl SqliteStorage {
         });
 
         if has_cjk {
-            // For CJK, use the full query as a quoted phrase for substring matching
-            // trigram will match any 3-char subsequence
-            if lower.len() >= 3 {
-                format!("\"{}\"", lower)
-            } else {
-                String::new()
+            // For CJK queries, extract tokens: CJK character sequences and ASCII words.
+            // Join with OR for broad matching (not exact phrase, which would miss scattered terms).
+            let mut tokens: Vec<String> = Vec::new();
+            let mut cjk_buf = String::new();
+            let mut ascii_buf = String::new();
+
+            for ch in lower.chars() {
+                let is_cjk = matches!(ch, '\u{4E00}'..='\u{9FFF}' | '\u{3400}'..='\u{4DBF}' | '\u{F900}'..='\u{FAFF}');
+                if is_cjk {
+                    if !ascii_buf.is_empty() {
+                        if ascii_buf.len() >= 2 {
+                            tokens.push(format!("\"{}\"", ascii_buf));
+                        }
+                        ascii_buf.clear();
+                    }
+                    cjk_buf.push(ch);
+                } else if ch.is_alphanumeric() {
+                    if !cjk_buf.is_empty() {
+                        // Flush CJK buffer — each CJK character is a potential token
+                        // (trigram indexes 3-char sequences, so single CJK chars won't
+                        // match alone, but 2+ char sequences will)
+                        if cjk_buf.len() >= 2 {
+                            tokens.push(format!("\"{}\"", cjk_buf));
+                        }
+                        cjk_buf.clear();
+                    }
+                    ascii_buf.push(ch);
+                } else {
+                    // Separator — flush both buffers
+                    if cjk_buf.len() >= 2 {
+                        tokens.push(format!("\"{}\"", cjk_buf));
+                    }
+                    cjk_buf.clear();
+                    if ascii_buf.len() >= 2 {
+                        tokens.push(format!("\"{}\"", ascii_buf));
+                    }
+                    ascii_buf.clear();
+                }
             }
+            // Flush remaining
+            if cjk_buf.len() >= 2 {
+                tokens.push(format!("\"{}\"", cjk_buf));
+            }
+            if ascii_buf.len() >= 2 {
+                tokens.push(format!("\"{}\"", ascii_buf));
+            }
+
+            if tokens.is_empty() {
+                return String::new();
+            }
+
+            tokens.join(" OR ")
         } else {
             // For non-CJK, split into terms and join with OR
             let terms: Vec<String> = lower