fix: 深度 review 修复 10 个 bug/问题

Critical & High:
- daemon 日志：启动时将 stdout/stderr 重定向到 ~/.wx-cli/daemon.log
  而非 /dev/null，使 wx daemon logs 真正可用
- q_history 找不到聊天时改为 bail! 而非 ok:true+error 字段，
  避免 CLI 静默返回空输出
- init 写 config.json 默认路径改为 ~/.wx-cli/config.json，
  避免写入系统 bin 目录（/usr/local/bin/config.json）
- LIKE 通配符：搜索关键词中的 %/_/\ 现在正确转义
- WAL 路径：改用 OsString.push 拼接 "-wal" 后缀，
  避免 display() 在非 UTF-8 路径上失效
- cmd_stop：检查 kill() 返回值，ESRCH 时给出明确提示

Performance & Code quality:
- full_decrypt：改为流式逐页读写，峰值内存从 2×文件大小降为 O(1)
- Regex：msg_table_re() 用 OnceLock 静态编译，避免热路径重复编译
- mtime_nanos：消除 daemon/mod.rs 与 cache.rs 的重复定义
- use super::super::cli::transport → use super::transport
- 删除未使用的 save_config、Request::to_json_line 死代码

src/daemon/cache.rs

@@ -80,11 +80,10 @@ impl DbCache {
                 continue;
             }
             let db_path = self.db_dir.join(rel_key.replace('\\', std::path::MAIN_SEPARATOR_STR).replace('/', std::path::MAIN_SEPARATOR_STR));
-            let wal_path_str = format!("{}-wal", db_path.display());
-            let wal_path = Path::new(&wal_path_str);
+            let wal_path = wal_path_for(&db_path);
 
             let db_mt = mtime_nanos(&db_path);
-            let wal_mt = if wal_path.exists() { mtime_nanos(wal_path) } else { 0 };
+            let wal_mt = if wal_path.exists() { mtime_nanos(&wal_path) } else { 0 };
 
             if db_mt == entry.db_mt && wal_mt == entry.wal_mt {
                 inner.insert(rel_key.clone(), CacheEntry {
@@ -135,8 +134,7 @@ impl DbCache {
             return Ok(None);
         }
 
-        let wal_path_str = format!("{}-wal", db_path.display());
-        let wal_path = Path::new(&wal_path_str).to_path_buf();
+        let wal_path = wal_path_for(&db_path);
 
         let db_mt = mtime_nanos(&db_path);
         let wal_mt = if wal_path.exists() { mtime_nanos(&wal_path) } else { 0 };
@@ -195,13 +193,20 @@ impl DbCache {
     }
 }
 
-fn mtime_nanos(path: &Path) -> u64 {
+pub(super) fn mtime_nanos(path: &Path) -> u64 {
     std::fs::metadata(path)
         .and_then(|m| m.modified())
         .map(|t| t.duration_since(std::time::UNIX_EPOCH).unwrap_or_default().as_nanos() as u64)
         .unwrap_or(0)
 }
 
+/// `foo/bar.db` → `foo/bar.db-wal`（用 OsString 拼接，避免 display() 的 UTF-8 问题）
+fn wal_path_for(db_path: &Path) -> PathBuf {
+    let mut name = db_path.file_name().unwrap_or_default().to_os_string();
+    name.push("-wal");
+    db_path.with_file_name(name)
+}
+
 fn hex_to_32bytes(s: &str) -> Result<[u8; 32]> {
     if s.len() != 64 {
         anyhow::bail!("密钥 hex 长度应为 64，实际为 {}", s.len());

src/daemon/mod.rs

@@ -208,12 +208,7 @@ async fn run_watcher(
     }
 }
 
-fn mtime_nanos(path: &std::path::Path) -> u64 {
-    std::fs::metadata(path)
-        .and_then(|m| m.modified())
-        .map(|t| t.duration_since(std::time::UNIX_EPOCH).unwrap_or_default().as_nanos() as u64)
-        .unwrap_or(0)
-}
+use cache::mtime_nanos;
 
 fn decompress_or_str(data: &[u8]) -> String {
     if data.is_empty() { return String::new(); }

src/daemon/query.rs

@@ -4,9 +4,16 @@ use regex::Regex;
 use rusqlite::Connection;
 use serde_json::{json, Value};
 use std::collections::HashMap;
+use std::sync::OnceLock;
 
 use super::cache::DbCache;
 
+/// 静态编译的 Msg 表名正则，避免在热路径中重复编译
+fn msg_table_re() -> &'static Regex {
+    static RE: OnceLock<Regex> = OnceLock::new();
+    RE.get_or_init(|| Regex::new(r"^Msg_[0-9a-f]{32}$").unwrap())
+}
+
 /// 联系人名称缓存
 #[derive(Clone)]
 pub struct Names {
@@ -141,7 +148,7 @@ pub async fn q_history(
 
     let tables = find_msg_tables(db, names, &username).await?;
     if tables.is_empty() {
-        return Ok(json!({ "error": format!("找不到 {} 的消息记录", display) }));
+        anyhow::bail!("找不到 {} 的消息记录", display);
     }
 
     let mut all_msgs: Vec<Value> = Vec::new();
@@ -218,7 +225,7 @@ pub async fn q_search(
                     .filter_map(|r| r.ok())
                     .collect();
 
-                let re = Regex::new(r"^Msg_[0-9a-f]{32}$").unwrap();
+                let re = msg_table_re();
                 let mut result = Vec::new();
                 for tname in table_names {
                     if !re.is_match(&tname) {
@@ -483,8 +490,10 @@ fn search_in_table(
     limit: usize,
 ) -> Result<Vec<Value>> {
     let id2u = load_id2u(conn);
-    let mut clauses = vec!["message_content LIKE ?".to_string()];
-    let mut params: Vec<Box<dyn rusqlite::types::ToSql>> = vec![Box::new(format!("%{}%", keyword))];
+    // 转义 LIKE 通配符，使用 '\' 作为 ESCAPE 字符
+    let escaped_kw = keyword.replace('\\', "\\\\").replace('%', "\\%").replace('_', "\\_");
+    let mut clauses = vec!["message_content LIKE ? ESCAPE '\\'".to_string()];
+    let mut params: Vec<Box<dyn rusqlite::types::ToSql>> = vec![Box::new(format!("%{}%", escaped_kw))];
     if let Some(s) = since {
         clauses.push("create_time >= ?".into());
         params.push(Box::new(s));