🎨 Palette: Accessible progressive character counter

[Sczitzo]

💡 What: Added a dynamic character counter that changes color (orange, then red) as the user approaches the input limit, along with conditionally rendered visually hidden status alerts for screen readers.

🎯 Why: The previous character counter was static and lacked accessible warnings. As users approached the limit, they were not visually or audibly warned, leading to potential frustration when input is cut off.

📸 Before/After:
Before: text-gray-500 static counter, no screen reader alerts.
After: Progressive color changes (text-orange-700 > text-red-600) and visually hidden role="status" messages at specific thresholds. Screenshot attached in verification.

♿ Accessibility: Instead of placing aria-live on the constantly changing counter (which causes annoying chatter on every keystroke), implemented conditionally rendered static elements at critical thresholds (80%, 90%, 100%) with role="status" to announce the limit warnings unobtrusively.

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PR created automatically by Jules for task 13416327536025466625 started by @Sczitzo

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