🎨 Palette: Accessible progressive character counter

[Sczitzo]

💡 What:

• Updated the character counter to provide progressive visual feedback (orange at 240, red at 300 characters).
• Added strictly static visually hidden elements with role="status" that only appear at key limits to warn screen readers without noisy keystroke updates.
• Removed a redundant aria-describedby="automaticThought-desc" from the optional automatic thought textarea, and its corresponding id on the span.

🎯 Why:

• Continuous character counters linked via aria-live or similar mechanisms cause overwhelming screen reader updates. Soft warnings at 80% and 100% capacity are safer and much more usable.
• The aria-describedby pointing to a span inside the <label> caused screen readers to announce "Automatic Thought (Optional)" and then immediately read "(Optional)" a second time.
• Visually, color-coding the limit approaches improves awareness for sighted users without requiring them to read tiny numbers.

📸 Before/After:
N/A - Minor visual text color tweaks and hidden accessibility fixes.

♿ Accessibility:

• Fixes double announcement issue on the Automatic Thought input label.
• Improves screen reader experience for text limits by using discrete state-driven warnings rather than noisy continuous updates.

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PR created automatically by Jules for task 13990461125492619451 started by @Sczitzo

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