fix(deployment): filter servers by selected path coverage (#544)

The server choosers listed every configured server without checking mapping coverage or exclusions, so choosing the wrong one silently skipped the files.

- Add a shared eligibility check, available through desktop IPC and host RPC, that never contacts a server.
- Filter Upload to, Download from, Compare and Delete choosers by it. A selection lists a server if it covers at least one path, and the rest are reported as skipped.
- Explain why the default server cannot take a selection, by file name, instead of doing nothing. Apply the same exclusion rules when a transfer runs.

Fixes #538

src/platform/locales/text/zh.json

@@ -5308,5 +5308,10 @@
   "Architecture": "架构",
   "Compiler": "编译器",
   "No CMake executable target for this file": "此文件没有对应的 CMake 可执行目标",
-  "Run CMake Configure from the Run selector, then choose the executable target. Files in a CMake project are built with their target.": "请从运行选择器执行 CMake Configure，然后选择可执行目标。CMake 项目中的文件由所属目标构建，不会单独编译。"
+  "Run CMake Configure from the Run selector, then choose the executable target. Files in a CMake project are built with their target.": "请从运行选择器执行 CMake Configure，然后选择可执行目标。CMake 项目中的文件由所属目标构建，不会单独编译。",
+  "Cannot check deployment mappings": "无法检查部署映射",
+  "No selected paths can be deployed to {server}": "所选路径均无法部署到 {server}",
+  "No deployment server covers the selected paths": "没有部署服务器覆盖所选路径",
+  "Not covered by this server's mappings": "此服务器的映射未覆盖该路径",
+  "Excluded from deployment": "已从部署中排除"
 }