Apply rustfmt pass across all modules

Pure whitespace normalization — no logic changes. Mostly:
- collapsing multi-line match/if arms rustfmt prefers inline
- inlining short `with_context`/`ok_or_else` closures
- reformatting nested method chains for consistency

Build and clippy stay clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/diagnose.rs

@@ -12,10 +12,18 @@ struct Check {
 
 impl Check {
     fn pass(label: impl Into<String>, detail: impl Into<String>) -> Self {
-        Self { label: label.into(), pass: true, detail: detail.into() }
+        Self {
+            label: label.into(),
+            pass: true,
+            detail: detail.into(),
+        }
     }
     fn fail(label: impl Into<String>, detail: impl Into<String>) -> Self {
-        Self { label: label.into(), pass: false, detail: detail.into() }
+        Self {
+            label: label.into(),
+            pass: false,
+            detail: detail.into(),
+        }
     }
 }
 
@@ -81,7 +89,10 @@ fn global_vulkan_check() -> Check {
     if ok {
         Check::pass("vulkan", "vulkaninfo OK")
     } else {
-        Check::fail("vulkan", "vulkaninfo failed — check GPU drivers / vulkan-tools")
+        Check::fail(
+            "vulkan",
+            "vulkaninfo failed — check GPU drivers / vulkan-tools",
+        )
     }
 }
 
@@ -130,10 +141,7 @@ fn wineserver_check(config: &Config) -> Check {
     if count == 0 {
         return Check::pass("wine procs", "no wineserver running");
     }
-    let any_running = config
-        .launchers
-        .iter()
-        .any(crate::launcher::is_running);
+    let any_running = config.launchers.iter().any(crate::launcher::is_running);
     if any_running {
         Check::pass(
             "wine procs",
@@ -142,9 +150,7 @@ fn wineserver_check(config: &Config) -> Check {
     } else {
         Check::fail(
             "wine procs",
-            format!(
-                "{count} stale wineserver process(es) — try: umutray kill"
-            ),
+            format!("{count} stale wineserver process(es) — try: umutray kill"),
         )
     }
 }
@@ -190,10 +196,7 @@ fn launcher_checks(l: &Launcher) -> Vec<Check> {
     }
 
     if is_owned_by_current_user(&l.prefix_dir) {
-        out.push(Check::pass(
-            format!("{tag} owner"),
-            "owned by current user",
-        ));
+        out.push(Check::pass(format!("{tag} owner"), "owned by current user"));
     } else {
         out.push(Check::fail(
             format!("{tag} owner"),