fix: 修复 review 发现的 4 个高优先级 bug

- Cargo.toml: libc 依赖范围从 macos 改为 unix（修复 Linux 编译失败）
- scanner/macos.rs: VM_REGION_BASIC_INFO_COUNT_64 改为硬编码 9（修复 mach_vm_region 调用失败）
- crypto/wal.rs: WAL 第一页帧不走主 DB 第一页特殊路径（修复 WAL 数据损坏）
- daemon/query.rs: 全局搜索传入正确 names_map（修复 sender 字段为空）

src/crypto/wal.rs

@@ -61,7 +61,9 @@ pub fn apply_wal(wal_path: &Path, out_path: &Path, enc_key: &[u8; 32]) -> Result
             page_buf.resize(PAGE_SZ, 0);
         }
 
-        let dec = decrypt_page(enc_key, &page_buf, pgno)?;
+        // WAL 帧中的页数据不含 SALT 头，所以对 pgno=1 的帧也用普通页解密路径
+        // （区别于主数据库第一页需要跳过 SALT 并写入 SQLite 魔数）
+        let dec = decrypt_page(enc_key, &page_buf, if pgno == 1 { 2 } else { pgno })?;
         let file_offset = (pgno as u64 - 1) * PAGE_SZ as u64;
         db_file.seek(SeekFrom::Start(file_offset))?;
         db_file.write_all(&dec)?;

src/daemon/query.rs

@@ -259,13 +259,14 @@ pub async fn q_search(
         let until2 = until;
         let limit2 = limit * 3;
 
+        let names_map2 = names.map.clone();
         let found: Vec<Value> = tokio::task::spawn_blocking(move || {
             let conn = Connection::open(&db_path)?;
             let mut all = Vec::new();
             for (tname, display, uname) in &table_list {
                 let is_group = uname.contains("@chatroom");
                 let rows = search_in_table(&conn, tname, &uname, is_group,
-                    &HashMap::new(), &kw2, since2, until2, limit2)?;
+                    &names_map2, &kw2, since2, until2, limit2)?;
                 for mut row in rows {
                     if row.get("chat").map(|v| v.as_str().unwrap_or("")).unwrap_or("").is_empty() {
                         if let Some(obj) = row.as_object_mut() {

src/scanner/macos.rs

@@ -152,9 +152,8 @@ fn scan_memory(task: mach_port_t) -> Result<Vec<(String, String)>> {
     let mut results: Vec<(String, String)> = Vec::new();
     let mut addr: mach_vm_address_t = 0;
 
-    // VM_REGION_BASIC_INFO_COUNT_64 = sizeof(vm_region_basic_info_64) / sizeof(int32_t)
-    let info_count_expected: mach_msg_type_number_t =
-        (std::mem::size_of::<VmRegionBasicInfo64>() / 4) as u32;
+    // VM_REGION_BASIC_INFO_COUNT_64 = 9（来自 <mach/vm_region.h>，固定值，不能用 sizeof 计算）
+    let info_count_expected: mach_msg_type_number_t = 9;
 
     loop {
         let mut size: mach_vm_size_t = 0;