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-tauri/src/commands/deploy.rs

@@ -1,9 +1,19 @@
 use crate::state::AppState;
 use ide_core::{IdeResult, IpcPath, RequestId};
-use ide_remote::{DeployedPath, SyncEntry, SyncStep, TransferReport};
+use ide_remote::{DeployedPath, DeploymentCoverage, SyncEntry, SyncStep, TransferReport};
 use ide_ssh::{FsConnection, RemoteEntry};
 use tauri::{State, Window};
 
+#[tauri::command]
+#[specta::specta]
+pub async fn deploy_coverage(
+    window: Window,
+    state: State<'_, AppState>,
+    paths: Vec<IpcPath>,
+) -> IdeResult<Vec<DeploymentCoverage>> {
+    ide_host::ops::deploy::deploy_coverage(window.label(), &state.host, paths).await
+}
+
 #[tauri::command]
 #[specta::specta]
 pub async fn deploy_upload(

src-tauri/src/commands/mod.rs

@@ -451,6 +451,7 @@ pub fn builder() -> tauri_specta::Builder<tauri::Wry> {
         ssh::git_credentials,
         ssh::git_credential_forget,
         ssh::ssh_terminal_command,
+        deploy::deploy_coverage,
         deploy::deploy_upload,
         deploy::deploy_download,
         deploy::deploy_delete_remote,