fix: 统一路径分隔符为正斜杠，修复 macOS/Linux 兼容性

all_keys.json 中的 key 统一使用 `/` 作为路径分隔符，
消除 Windows 反斜杠硬编码，确保跨平台兼容。

涉及文件: find_all_keys.py, decrypt_db.py, monitor.py,
monitor_web.py, mcp_server.py, decode_image.py, latency_test.py

Fixes #17

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

decrypt_db.py

@@ -129,7 +129,7 @@ def main():
         for f in files:
             if f.endswith('.db') and not f.endswith('-wal') and not f.endswith('-shm'):
                 path = os.path.join(root, f)
-                rel = os.path.relpath(path, DB_DIR)
+                rel = os.path.relpath(path, DB_DIR).replace('\\', '/')
                 sz = os.path.getsize(path)
                 db_files.append((rel, path, sz))
 
@@ -142,8 +142,8 @@ def main():
     total_bytes = 0
 
     for rel, path, sz in db_files:
-        # 用反斜杠格式查找key (json中的key是Windows路径)
-        rel_key = rel.replace('/', '\\')
+        # 统一用正斜杠查找key
+        rel_key = rel.replace('\\', '/')
         if rel_key not in keys:
             print(f"SKIP: {rel} (无密钥)")
             failed += 1