refactor(forms): retire InputGroup component prop

[talissoncosta]

Thanks for submitting a PR! Please check the boxes below:

• I have read the Contributing Guide.
• I have added information to docs/ if required so people know about the feature.
• I have filled in the "Changes" section below.
• I have filled in the "How did you test this code" section below.

Changes

Contributes to #7364. Stacked on the SelectField PRs (base: refactor/select-semantic-tokens). Opened as a draft spike to validate the full migration against CI E2E before splitting into review batches.

Migrates every <InputGroup component={...} /> call site and deletes the prop:

• 10 Select sites → SelectField (the CreatePipelineStage red-border hack becomes the error prop).
• 15 custom-control sites (metadata, date picker, colour picker, value editor, switch...) → FieldLabel + a plain form-group wrapper.
• component removed from InputGroup, with a lint rule so it stays gone.
• Fake "Select a..." default options become react-select's placeholder (grey placeholder text instead of a value-looking default).
• Utils.toSelectedValue is now generic; its old signature was wrong for every caller. Handlers that ignored react-select's null case got guards.

How did you test this code?

• tsc: 0 new errors vs the base branch, 21 baseline errors fixed.
• eslint: clean on all 27 changed files; the new lint rule confirms no component= remains.
• This PR exists to check CI E2E; manual QA of each migrated screen pending.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
flagsmith-frontend-preview	Ready	Preview, Comment	Jul 27, 2026 6:19pm
flagsmith-frontend-staging	Ready	Preview, Comment	Jul 27, 2026 6:19pm

1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
docs	Ignored		Jul 27, 2026 6:19pm

[coderabbitai]

Important

Review skipped

Draft detected.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Organization UI

Review profile: ASSERTIVE

Plan: Pro Plus

Run ID: 20f171d3-47df-44bd-8634-5913c73626cf

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[talissoncosta]

Closing: this was a sizing/validation spike for retiring the component prop, and the work is now split into #8120/#8121/#8122 under #8119, to be tackled individually. One caveat for the follow-ups: CI skipped the E2E jobs here (draft, stacked base), so the spike only proved compile-time completeness; the #8122 batches should get their E2E signal on their own PRs. The branch stays around as a reference for the per-site transforms.