feat(wallets): refresh the rename wallet modal

[CassioMG]

Part of the Home refresh project.

What changed

The rename-wallet modal, per Figma frame 9585-24423:

• The card is now centred instead of pinned at top: 30%.
• Circular X close button top-right inside the card.
• Centred identicon above the input.
• "Save" → "Set name", and Cancel / Set name sit side by side at equal width.
• Removed: the "Rename Wallet" heading and the Address: G… line.

The form itself is untouched — same Formik setup, same 24-character Yup limit, same dispatch.

Two bugs found and fixed while implementing

1. The modal was unclickable. Centring with transform: translateY(-50%) creates a new CSS stacking context, which let the sibling LoadingBackground backdrop sit above the card and swallow every click. Fixed by adding z-index: var(--z-index--banner) to the same wrapper block. Caught by actually clicking it in a browser, not by code review — worth knowing if you centre another overlay this way.
2. variant="primary" was wrong for the "Set name" button. In SDS, primary is a purple fill; secondary is the near-white fill with black text that the frame shows (--sds-clr-gray-12 background, --sds-clr-base-00 text). Using secondary.

Scoped to avoid conflicts

views/Wallets/styles.scss is shared by three PRs in this batch. This PR changes only the .RenameWalletWrapper block — .AddWalletWrapper and everything else are untouched. The diff on that file is 5 lines.

Merge order

• The wallets-list PR should merge before this one. Both touch views/Wallets/styles.scss, and it deletes the largest region of that file.
• Heads-up: this PR also changes one line in extension/e2e-tests/loadAccount.test.ts ("Save" → "Set name", since that test asserts the button label). The wallets-list PR rewrites the rename navigation in that same test, so expect a small conflict there — take both changes: the new navigation and the new label.

Analytics

Unchanged. emitMetric(METRIC_NAMES.accountRenamed, { source: "wallets" }) is byte-identical, verified by grep.

One thing for the designer

The frame's backdrop is #000000e5 — black at ~90%. This PR reuses the existing LoadingBackground component at its --active opacity of 0.6, rather than hardcoding a new rgba or adding a one-off opacity variant for a single modal. If the darker scrim matters visually, that's a deliberate call to make rather than something I'd sneak in.

Verification

• yarn test:ci — 196/202 suites, 1520/1571 tests, identical to baseline
• yarn build:extension — clean
• yarn test:e2e loadAccount.test.ts — 9 passed / 2 skipped, matching baseline
• Clicked through the modal in a real browser build (that's how bug 1 surfaced)

Known repo issue

yarn build:extension:translations is broken on master (i18next-scanner-webpack needs .default, extension/webpack.extension.js:3), and the pre-commit hook hides the failure. The one new locale key here was added by hand to en and pt. Worth fixing separately.

🤖 Generated with Claude Code

[github-actions]

PR Preview build is ready: https://github.com/stellar/freighter/releases/tag/untagged-8565efb64d42e48b710d (SDF collaborators only — install instructions in the release description)