feat(mac): add push-to-talk hotkey

apps/macos/Tests/ClawdisIPCTests/VoicePushToTalkTests.swift

@@ -0,0 +1,24 @@
+import Testing
+@testable import Clawdis
+
+@Suite struct VoicePushToTalkTests {
+    @Test func deltaTrimsCommittedPrefix() {
+        let delta = VoicePushToTalk._testDelta(committed: "hello ", current: "hello world again")
+        #expect(delta == "world again")
+    }
+
+    @Test func deltaFallsBackWhenPrefixDiffers() {
+        let delta = VoicePushToTalk._testDelta(committed: "goodbye", current: "hello world")
+        #expect(delta == "hello world")
+    }
+
+    @Test func attributedColorsDifferWhenNotFinal() {
+        let colors = VoicePushToTalk._testAttributedColors(isFinal: false)
+        #expect(colors.0 != colors.1)
+    }
+
+    @Test func attributedColorsMatchWhenFinal() {
+        let colors = VoicePushToTalk._testAttributedColors(isFinal: true)
+        #expect(colors.0 == colors.1)
+    }
+}