Update cost center budget setup guidance

[BenDutton]

GitHub now supports managing cost center AI credit pools directly in the billing UI, so the guide's API-first instructions were obsolete and overly prominent.

This update:

• makes the UI workflow the primary recommendation for isolating cost center usage
• explains that GitHub calculates the pool limit from assigned Copilot licenses
• distinguishes the AI credit pool limit from the separate budget that caps metered charges
• removes the obsolete API reference section and links to current GitHub guidance

Validation:

• npx eslint src/components/tools/budget-guidance.tsx --quiet
• npm run build

The repository-wide lint remains blocked by an existing react-hooks/set-state-in-effect error in src/components/use-prefers-reduced-motion.ts.

[Copilot]

Pull request overview

Updates the Budget Setup Guide tool content to reflect GitHub’s newer UI-first workflow for configuring cost center AI credit pools, removing obsolete API-centric guidance and aligning supporting docs/styling.

Changes:

• Renames and reframes the “included-usage control” guidance as “AI credit pool”, with updated UI-based setup steps and notes.
• Removes the obsolete REST API reference section and refreshes “References & further reading” links to current GitHub docs/changelog.
• Cleans up CSS module styles that were only used by the removed reference table; updates tool documentation accordingly.

Show a summary per file

File	Description
src/components/tools/budget-guidance.tsx	Updates use-case guidance text and references to be UI-first for AI credit pools; removes obsolete API reference section.
src/components/app.module.css	Removes styles for the deleted AI credit pool reference table and updates related header comment.
docs/tools.md	Updates the Budget Setup Guide description to match the new AI credit pool UI-first guidance.

Review details

Comments suppressed due to low confidence (1)

src/components/tools/budget-guidance.tsx:459

• This reference note switches terminology to “included-credit limit”, while the rest of the guide uses “AI credit pool”. Keeping the term consistent here will reduce reader confusion.

            </Link>
            <span className={styles.muted}>
              {" "}— enabling and configuring a cost center&apos;s included-credit limit.
            </span>

• Files reviewed: 3/3 changed files
• Comments generated: 1
• Review effort level: Low