🎨 Palette: Improve screen reader accessibility for icon-only buttons

[Bhishaj9]

This PR implements critical accessibility fixes for screen reader compatibility, specifically targeting "icon-only" buttons and links where visual text is missing or hidden responsively.

Changes:

• dashboard.html, glassui.html, code.html: Added aria-label to "Back to Home", "Deploy", "Copy JSON", and "Download JSON" buttons/links. Added aria-hidden="true" to the associated Google Material Symbols <span> tags to prevent screen readers from reading out raw ligatures (like "rocket_launch").
• landingpage.html: Added an aria-label to the "Enter corporate email" <input type="email"> field which previously lacked one.
• Documentation: Created a .jules/palette.md UX journal entry documenting the learnings and patterns required for responsive icon buttons.
• Formatting: Applied prettier --write consistently across modified templates.
• Verification: Included Playwright visual/DOM a11y checks ensuring elements remain properly accessible.

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PR created automatically by Jules for task 14707823851332958829 started by @Bhishaj9

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