refactor(config): alphabetize the instance Config nav items

[dawsontoth]

Stacked on #1402 (the cluster Secrets page). Review the top commit only; everything below belongs to #1402. Retarget to stage once #1402 (and its own base #1409) land.

What

Reorders the instance Config page nav so the items read alphabetically. Overview stays pinned at the top and keeps its divider (border-t) from the rest — only the items below the divider move.

Before → after:

Before (order added)	After (alphabetical)
Users	Certificates
Roles	Deployments
Deployments	Domains
Certificates	Roles
Domains	Secrets
SSH Keys	SSH Keys
Secrets	Users

(“Secrets” is the entry #1402 adds; it slots in alphabetically here so the two PRs don't fight over ordering.)

Only the JSX order in src/features/instance/config/index.tsx changed. Every item keeps its icon and its existing version/permission gate (certsAvailable, deploymentsAvailable, secretsSupported, self-managed/local checks) — nothing was added or removed, just resequenced. Icon imports were already alphabetized on the base branch, so no import change.

Verification

• Full suite green (1275 passed), tsc, oxlint, dprint all clean via the pre-commit hooks.
• Rendered menu order maps 1:1 to the static JSX order, verified at the source level. Not click-tested in a browser: port 5173 is held by a different checkout and a fresh-origin dev server hits the auth wall, so the live Config page wasn't reachable this session.

🤖 Generated with Claude Code

[gemini-code-assist]

Code Review

This pull request reorganizes the navigation links in the configuration index page to be in alphabetical order, including Certificates, Deployments, Roles, Secrets, SSH Keys, and Users. There are no review comments, and I have no additional feedback to provide.