Honor quiet update mode in installers

tests/release_scripts.rs

@@ -6,6 +6,12 @@ fn quiet_update_keeps_prebuilt_enabled_by_default() {
         !install.contains("use_prebuilt=0"),
         "quiet updates must not force source builds"
     );
+    assert!(install.contains("[ \"$quiet\" != \"1\" ] && echo \"Trying Dosh prebuilt"));
+    assert!(install.contains("[ \"$quiet\" != \"1\" ] && echo \"Building Dosh $role\""));
+    assert!(
+        !install.contains("[ \"$quiet\" = \"1\" ] && echo"),
+        "quiet updates must suppress informational installer output"
+    );
 }
 
 #[test]
@@ -159,6 +165,25 @@ fn windows_installer_bootstraps_rust_for_source_fallback_like_unix() {
     assert!(!ps1.contains("Require-Command cargo"));
 }
 
+#[test]
+fn windows_installer_honors_quiet_update_mode() {
+    let ps1 = include_str!("../install.ps1");
+    assert!(ps1.contains("$Quiet = $env:DOSH_UPDATE_QUIET"));
+    assert!(ps1.contains("function Write-Info($Message)"));
+    assert!(ps1.contains("if (-not $Quiet)"));
+    assert!(ps1.contains("Write-Info \"Trying Dosh prebuilt"));
+    assert!(ps1.contains("Write-Info \"Falling back to source build\""));
+    assert!(ps1.contains("Write-Info \"Installed Dosh client to $bindir\""));
+    assert!(
+        !ps1.contains("Write-Host \"Trying Dosh prebuilt"),
+        "Windows quiet update must not print prebuilt progress directly"
+    );
+    assert!(
+        !ps1.contains("Write-Host \"Installed Dosh client"),
+        "Windows quiet update must not print install summary directly"
+    );
+}
+
 #[test]
 fn windows_installer_adds_user_path_idempotently() {
     let ps1 = include_str!("../install.ps1");