Restore XCP Wallet privacy and terms pages

[droplister]

The Chrome Web Store and installed wallet link to /privacy, which became a 404 after xcp.io switched to the explorer. /terms was also missing.

Restore both pages from XCP/xcp.io with their published text and effective dates, adapting metadata and styling for the explorer. Add explicitly labeled XCP Wallet policy links to the footer.

Validation:

• npm run check passes locally; both CI jobs pass, including the Linux OpenNext build, browser tests, and production prefetch checks.
• Both routes return HTTP 200 locally and render without horizontal overflow at 390px and 1280px; screenshots inspected.
• Rendered article text matches the original policy pages exactly after whitespace normalization.

Deployed to xcp-web (version 12c129b5-c9df-48ba-9467-60fa6918e06e). Verified public HTTP 200 and the correct policy content at both www and apex /privacy and /terms URLs. Live mobile browser checks passed, and the homepage includes the new policy links.