🎨 Palette: Add progressive character limit warnings

[Sczitzo]

💡 What: Replaced the static character counter on the alternativeThought textarea with a dynamic one that provides progressive visual feedback (turns orange at 80% capacity and red at 90% capacity).
🎯 Why: To provide users with clear, intuitive feedback about how close they are to the 300-character limit, reducing friction and preventing unexpected cut-offs during data entry.
📸 Before/After: The counter text color progresses from gray to orange to red.
♿ Accessibility: Added conditional, visually hidden role="status" elements that mount at specific thresholds (80%, 90%, 100%) to provide static screen reader warnings without announcing every single keystroke.

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PR created automatically by Jules for task 3735551552001129789 started by @Sczitzo

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[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Keep the live region mounted before updating it

For screen-reader users crossing the 80%, 90%, or 100% thresholds, these role="status" nodes are inserted already containing their final text, and many assistive-tech stacks only announce changes inside an existing live region rather than initial content on a newly mounted non-alert region. The warning can therefore be silent in the exact accessibility path this change adds; keep one hidden status region mounted and update its text when the threshold bucket changes.

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