helium/ui/find-bar: add match case and whole word toggles to find menu

[finaIcutpro]

For your pull request to not get closed without review, please confirm that:

• An issue exists where the maintainers agreed that this should be implemented
  (an approved feature request, or confirmed bug).
• I tested that my contribution works locally, and does not break anything,
  otherwise I have marked my PR as draft.
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Tested on (check one or more):

• Windows
• macOS
• Linux

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I found it annoying to have to deal with exact word and case sensitive matching in the Cmd + F menu. This fixes that.

Screen.Recording.2026-10-19.at.9.51.37.PM.mov

[greptile-apps]

[Medium impact] The change affects the browser's find-in-page workflow.

The PR appears safe to merge, with a non-blocking issue where open windows can overwrite each other's search options.

_{Reviews (1) · Last reviewed commit: "add find in page switches" · Reviewed by Greptile}

[finaIcutpro]

I have no further changes I want to make && am happy with the code. I believe this is ready to merge.

[helium-gardener]

Possibly related issues

These relationships were inferred from the effective change and may need maintainer confirmation:

• May be resolved by this PR: imputnet/helium#311 — Adds the requested case-sensitive find-bar control and routes it through find requests to Blink's case-sensitive matcher; also adds the whole-word option discussed on the issue.

[helium-gardener]

Found four actionable correctness issues involving cached iframe matches, PDF searches, and shared find-option state.

Review walkthrough

Changes

Files	Summary
patches/helium/core/find-exact-match.patch	Adds whole_word to Mojo find options and forwards it to Blink's active-match and scoping matchers. Reviewed renderer caching and the separate plugin/PDF path.
patches/helium/ui/find-bar-options.patch	Adds animated option rows, profile-level matching state, and search-session detection for option changes. Reviewed callbacks, ownership, focus handling, cross-window synchronization, and PDF restarts.
i18n/source.gen.json patches/series	Registers three matching UI strings and orders the renderer prerequisite before the UI patch, which follows the existing find-bar patch.

Review checks

Check	Result	Notes
Scope	✅ Passed	Confirmed four changed repository files and ten effective Chromium targets. No version transition or patch-application warnings; reported locations match reviewable provenance.
Project Policy	✅ Passed	Neither new patch changes upstream tests, test data, expectations, or test targets.
Correctness And Safety	⚠️ Finding	Identified stale renderer caches, two PDF integration defects, and unsynchronized shared controls. Reviewed desktop build wiring, lifetime, and incognito service separation.
Chromium Idioms	✅ Passed	The implementation uses existing Blink whole-word matching, Views builders, toggle controls, and animation APIs.
Simplicity And Decomposition	✅ Passed	The row helper and callbacks have local responsibilities; no separate actionable abstraction or decomposition concern.
Patch Organization	✅ Passed	Renderer support and UI integration are coherent patches, with prerequisites ordered correctly and UI work adjacent to the existing find-bar patch.

Analysis record

• Changed files considered: 4
• Findings: 4 new, 0 retained, 0 resolved
• Source snapshot: e5b1aeac84f7
• Codex: gpt-6.1-sol, reasoning max, fast mode on, web search cached
• Patch application: clean
• Chromium context tool calls: none
• Maintainer conventions applied: ignore-disabled-telemetry, preserve-incremental-loading, script-resource-lifecycle, ui-command-contexts, validate-supported-ui-paths, verify-runtime-selection-paths, visible-ui-anchors

Limitations

• Static inspection only; builds, tests, and interactive UI validation were not run.
• The supplied screenshots were available, but the PR's video attachment was unavailable.

[finaIcutpro]

all gardener suggestions have been triaged && resolved