Fix text input focus loss in searchbar/textfield

[jserv]

Text input components were losing focus every frame because they failed to register with the field tracking system. The tracking system clears ctx->focused_edit at frame end for unregistered buffers.

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Summary by cubic

Fixed focus loss in text inputs by registering buffers with the per-frame tracking system. Textfield and search bar now keep focus while typing across frames.

• Bug Fixes
  • Register text fields via iui_register_textfield in iui_textfield_with_selection and iui_search_bar_ex.
  • Auto-focus and register search->query in iui_search_view_begin.
  • Prevent ctx->focused_edit from being cleared for active inputs.

^{Written for commit 41c4b76. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 2 files