Code review comment fixes and some refactors. (#525)

No intentional different behavior aside for tweaks suggested from the code review of #506 Refactor: Extract console message logic to custom hook

This commit refactors the console message handling from App.tsx into a new custom hook useConsoleMessages.

This change improves the testability of the console message logic and declutters the main App component.

Created useConsoleMessages.ts to encapsulate console message state and update logic.
Updated App.tsx to utilize the new useConsoleMessages hook.
Added unit tests for useConsoleMessages.ts to ensure its functionality.
I deleted and started over on LoadingIndicator.test.tsx as I spent way too much time trying to fix it before just regenerating the tests as the code was easier to write tests for from scratch and the existing tests were not that good (I added them in the previous pull request).

packages/cli/src/ui/hooks/usePhraseCycler.ts

@@ -0,0 +1,84 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { useState, useEffect, useRef } from 'react';
+
+export const WITTY_LOADING_PHRASES = [
+  'Consulting the digital spirits...',
+  'Reticulating splines...',
+  'Warming up the AI hamsters...',
+  'Asking the magic conch shell...',
+  'Generating witty retort...',
+  'Polishing the algorithms...',
+  "Don't rush perfection (or my code)...",
+  'Brewing fresh bytes...',
+  'Counting electrons...',
+  'Engaging cognitive processors...',
+  'Checking for syntax errors in the universe...',
+  'One moment, optimizing humor...',
+  'Shuffling punchlines...',
+  'Untangling neural nets...',
+  'Compiling brilliance...',
+];
+
+export const PHRASE_CHANGE_INTERVAL_MS = 15000;
+
+/**
+ * Custom hook to manage cycling through loading phrases.
+ * @param isActive Whether the phrase cycling should be active.
+ * @param isWaiting Whether to show a specific waiting phrase.
+ * @returns The current loading phrase.
+ */
+export const usePhraseCycler = (isActive: boolean, isWaiting: boolean) => {
+  const [currentLoadingPhrase, setCurrentLoadingPhrase] = useState(
+    WITTY_LOADING_PHRASES[0],
+  );
+  const phraseIntervalRef = useRef<NodeJS.Timeout | null>(null);
+  const currentPhraseIndexRef = useRef<number>(0);
+
+  useEffect(() => {
+    if (isWaiting) {
+      setCurrentLoadingPhrase('Waiting for user confirmation...');
+      if (phraseIntervalRef.current) {
+        clearInterval(phraseIntervalRef.current);
+        phraseIntervalRef.current = null;
+      }
+    } else if (isActive) {
+      if (phraseIntervalRef.current) {
+        clearInterval(phraseIntervalRef.current);
+      }
+      // Reset to the first witty phrase when starting to respond
+      currentPhraseIndexRef.current = 0;
+      setCurrentLoadingPhrase(WITTY_LOADING_PHRASES[0]);
+
+      phraseIntervalRef.current = setInterval(() => {
+        currentPhraseIndexRef.current =
+          (currentPhraseIndexRef.current + 1) % WITTY_LOADING_PHRASES.length;
+        setCurrentLoadingPhrase(
+          WITTY_LOADING_PHRASES[currentPhraseIndexRef.current],
+        );
+      }, PHRASE_CHANGE_INTERVAL_MS);
+    } else {
+      // Idle or other states, clear the phrase interval
+      // and reset to the first phrase for next active state.
+      if (phraseIntervalRef.current) {
+        clearInterval(phraseIntervalRef.current);
+        phraseIntervalRef.current = null;
+      }
+      setCurrentLoadingPhrase(WITTY_LOADING_PHRASES[0]);
+      currentPhraseIndexRef.current = 0;
+    }
+
+    return () => {
+      if (phraseIntervalRef.current) {
+        clearInterval(phraseIntervalRef.current);
+        phraseIntervalRef.current = null;
+      }
+    };
+  }, [isActive, isWaiting]);
+
+  return currentLoadingPhrase;
+};