🎨 Palette: Add required attribute to operator token input

[mapleleaflatte03]

💡 What: Added the required HTML attribute to the "Operator token" input field on the trust-ops.html operator surface.
🎯 Why: Without this attribute, operators could accidentally submit the unlock queue form with a blank token, bypassing native browser validation.
📸 Before/After: Before, submitting the form blank sent a request. After, native HTML5 validation stops submission with a "Please fill out this field" bubble.
♿ Accessibility: Assistive technologies (like screen readers) will now announce the token field as a required input, improving accessibility for impaired operators.

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PR created automatically by Jules for task 1849742717594548722 started by @mapleleaflatte03

[google-labs-jules]

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