docs: add scoop install git prereq to Windows install steps

[bpamiri]

Summary

Real-user run from a fresh Windows shell surfaced a missing prerequisite: Scoop's installer doesn't ship git, but `scoop bucket add` uses `git clone` under the hood, so adding any third-party bucket fails with:

```
ERROR Git is required for buckets. Run 'scoop install git' and try again.
```

`scoop install git` itself works from a totally fresh shell because the default `main` bucket — where git lives — is bundled with the Scoop installer rather than fetched at runtime. So the corrected sequence is:

```powershell
Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser
Invoke-RestMethod -Uri https://get.scoop.sh | Invoke-Expression
scoop install git # NEW STEP
scoop bucket add wheels https://github.com/wheels-dev/scoop-wheels
scoop install wheels
```

Files

• `web/sites/guides/src/content/docs/v4-0-{0,1-snapshot}/start-here/installing.mdx` — added as a numbered step with prose explanation.
• `web/sites/guides/src/content/docs/v4-0-{0,1-snapshot}/command-line-tools/installation.mdx` — added inline as a code comment + line of explanation.

Why we missed this in #2761/#2762

Previous PRs were updating the docs based on the dependency story (was `scoop bucket add java`, then dropped after #4 inlined the JDK). The git-clone-for-bucket prerequisite is a Scoop infrastructure concern, not a Wheels package concern — it's the same prereq for any third-party Scoop bucket, and easy to overlook when you have git already installed on your dev machine. Caught by a fresh-shell test today.

Test plan

• Astro guides build is green (`pnpm --dir web/sites/guides build`).
• On a fresh Windows shell with no git: the new step sequence completes without errors.
• Rendered `installing.mdx` Steps blocks show 4 steps (was 3) for the Windows tab; numbering looks right.

Follows on from #2761 and #2762.

[wheels-bot]

Wheels Bot — Reviewer A

TL;DR: This PR adds a missing scoop install git prerequisite to the Windows installation guide across both doc versions (v4-0-0 and v4-0-1-snapshot). The fix is correct, well-explained, and consistently applied — verdict: approve.

Correctness

The fix is accurate. Scoop's bucket add sub-command calls git clone internally, so any third-party bucket addition fails without git on PATH. The explanation that the default main bucket ships bundled with the Scoop installer — enabling scoop install git to succeed from a completely fresh shell — is correct and worth documenting.

Both touch points are updated consistently:

• start-here/installing.mdx breaks out a dedicated Step 2 with a clear "skip if git --version already works" escape hatch — good UX for developers who already have git.
• command-line-tools/installation.mdx injects scoop install git inline into the existing code block with an inline comment carrying the bootstrapping rationale. Keeping it inside the same fence (rather than a new step) matches the denser reference style of that doc.

Step renumbering in installing.mdx (2→3 "Add bucket", 3→4 "Verify") is correct in both versions.

Commits

docs: add \scoop install git` prerequisite before bucket add— typedocs, no scope, subject under 100 chars, sentence-case. Clean against commitlint.config.js`.

[wheels-bot]

Wheels Bot — Reviewer B (round 1)

A's review is clean. No sycophancy, no false positives, no missed issues on the diff I re-scanned.

Sycophancy

None detected. A cited specific reasons: explained why the fix is technically correct (Scoop's bucket add calls git clone internally, while the main bucket is the exception because its metadata is bundled with the Scoop installer), verified consistency across all four changed files, and confirmed the step renumbering. The approval is earned, not assumed.

False positives

None detected. I re-verified A's specific claims against the diff:

• All four files updated consistently (v4-0-0 and v4-0-1-snapshot, both installing.mdx and installation.mdx) -- confirmed.
• Step renumbering (old step 2 becomes 3, old step 3 becomes 4) in both installing.mdx versions -- confirmed correct.
• Commit docs: add scoop install git prerequisite before bucket add: docs type, no scope, subject 59 chars, sentence-case -- passes commitlint.config.js.

A's observation that installation.mdx uses an inline-comment style rather than a new numbered step is accurate and correct for that doc's format.

Missed issues

None detected. Pure MDX documentation change -- no CFML, no framework code, no migrations, no security surface. Cross-engine compatibility checks are not applicable here.

Verdict alignment

Approve is consistent with A's findings. All changes are accurate, consistently applied, and technically sound.

Convergence

Aligned. A's review is correct and the approve verdict is right.