Add hint tooltip to qualifying markdown textareas

[Copilot]

• Create src/content/hint-tooltip.ts module for tooltip logic
• Show tooltip on focus of qualifying textareas (when picker is not open)
• Hide tooltip when picker opens
• Hide tooltip on blur
• Reposition tooltip on scroll/resize
• Refresh tooltip styles on theme change
• Add E2E tests for hint tooltip visibility
• Fix prettier formatting in hint-tooltip.ts

Original prompt

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This section details on the original issue you should resolve

<issue_title>Show hint tooltip next to text areas that work with the plugin</issue_title>
<issue_description>Display an independent small tooltip, for the text areas that qualify, with the hint to type "//" to open the command list.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Show hint tooltip next to text areas that work with the plugin #91

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[da-ba]

@copilot
prettier formatting fails, fix it.

[Copilot]

@copilot
prettier formatting fails, fix it.

Fixed in ec62800 — ran prettier --write on src/content/hint-tooltip.ts.

[github-actions]

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🔗 https://da-ba.github.io/gsp/pr-95-ec62800/

Version: 0.0.6 | Build: PR#95@ec62800

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