Show profile paths, report the build version, and colour each profile

- Selecting a row in the Profiles tab shows its Claude Desktop and Claude
  Code dirs inline and selectable, instead of requiring a right-click
  "Reveal in Finder" to find out where a profile actually lives.
- build.sh stamps Contents/Resources/COMMIT with the short HEAD SHA, left
  empty when HEAD sits exactly on a tag (how a real release is built),
  since the version number alone is unambiguous there. About appends it
  when present, so two dev builds off the same VERSION are
  distinguishable. The update checker still compares plain semver.
- Profile dot colours are picked per NSApp.effectiveAppearance at render
  time: same hue either way, but full saturation with brightness split
  per background (1.0 dark, 0.55 light), so they read as bold hues rather
  than washing out on white or muddying against a dark menu.

Sources/UpdateChecker.swift

@@ -33,6 +33,21 @@ enum UpdateChecker {
         return contents.trimmingCharacters(in: .whitespacesAndNewlines)
     }
 
+    // What the About panel shows: the version alone for a real release
+    // build (COMMIT is written empty when build.sh finds HEAD sitting
+    // exactly on a tag), or version + short SHA for a dev build, so two
+    // local builds off the same version number are distinguishable.
+    static var displayVersion: String {
+        commitSHA.isEmpty ? currentVersion : "\(currentVersion) (\(commitSHA))"
+    }
+
+    private static var commitSHA: String {
+        guard let resourceURL = Bundle.main.resourceURL,
+              let contents = try? String(contentsOf: resourceURL.appendingPathComponent("COMMIT"), encoding: .utf8)
+        else { return "" }
+        return contents.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
     static func checkManually(completion: @escaping (Outcome) -> Void) {
         fetchLatestVersion { latest in
             guard let latest else { completion(.failed); return }