Make EntityPicker auto focus on search field when it appears

[Copilot]

Summary

Adds auto-focus to the EntityPicker search field using SwiftUI's @FocusState. When the picker appears, the keyboard opens automatically, allowing immediate search without an extra tap.

@FocusState private var isSearchFocused: Bool

TextField(...)
    .focused($isSearchFocused)

.onAppear {
    isSearchFocused = true
}

Follows the existing pattern used in AssistView.swift.

Screenshots

N/A - keyboard behavior change only.

Link to pull request in Documentation repository

N/A - no documentation changes required.

Any other notes

None.

Original prompt

Make EntityPicker auto focus on search field when it appears

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Codecov Report

✅ All modified and coverable lines are covered by tests.
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Additional details and impacted files

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  Files           ?      261           
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  Hits            ?     6502           
  Misses          ?     8592           
  Partials        ?        0           

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[Copilot]

Pull request overview

This PR updates the EntityPicker SwiftUI view so that its search field automatically gains focus (and shows the keyboard) when the picker appears, improving usability.

Changes:

• Added an @FocusState-backed property (isSearchFocused) to EntityPicker.
• Bound the search TextField to this focus state using .focused($isSearchFocused).
• Set isSearchFocused = true in content.onAppear so the search field becomes first responder when the picker view appears (including inline and sheet modes).