fix(console): dashboard balance, fleet link loop, adopt stepper and a way back from certificates

[Bugs5382]

What and why

Four fixes from my console design review (Closes #199):

• The dashboard grid was five cards, which leaves an uneven last row at common widths. I added a sixth card, Recent activity, built from the audit log data the console already loads, so the grid is even everywhere and there's a reason to glance at the dashboard beyond the per-surface counts.
• The fleet topology panel's "Open node" link still showed on the node's own detail page, pointing back at the page already on screen. I gave NodeDetailPanel a showOpenNodeLink prop (default true) and turned it off on the node detail page; the topology panel keeps it.
• The adopt wizard was capped at max-w-xl and tracked its own steps only with plain headings. I made it full width and added the kit's Stepper across the top (Endpoint, Initial config, Provisioning), driven by the same state the form already uses.
• A single certificate's page only linked back to its node, with no direct path to Certificates. I added a breadcrumb (Certificates > the certificate) above the heading, alongside the existing "Back to node" button.

Verification

• apps/console/src/pages/dashboard.test.tsx: the Recent activity card links to /audit and shows the latest audit entry.
• apps/console/src/components/node-detail-panel.test.tsx: Open node shows by default and hides when showOpenNodeLink is false; apps/console/src/pages/node-detail.test.tsx confirms it's gone from the node's own page.
• apps/console/src/pages/adopt.test.tsx: the page is no longer max-w-xl, and the stepper's current step moves from Endpoint to Initial config once the fingerprint is confirmed.
• apps/console/src/pages/node-cert-detail.test.tsx: the Certificates breadcrumb link and the existing Back to node link both resolve to the right paths.
• Every new and touched test runs expectNoA11yViolations.

How this was verified

CI is the proof here (lint, vitest, build); I didn't run a local build or test pass.