refactor(site): move the remaining site files no pending change touches into their owner folders

[apresmoi]

What changed

• Second S4 pull request: 33 files move into their owner folders with apply-moves.mts (3 source files and 30 tests), using the map in .github/site-refactor.json. Root files in site/, tracked: 100 to 93 in total, 60 to 57 without tests.
• The moved sources are prepared-arrival.mts, moon-catalogue.mts and surrounded-body.mts. surrounded-body.mts was new on main and had no destination, so it is assigned to world/ with its test. The tests move with their subjects or, for the old site/test/ files, into the folder of the code they cover.
• Imports, new URL(...) literals, docs links, code spans, the coverage ratchet floors and ci-areas.json follow the moves. moves.json loses the applied entries, tiers.json follows its paths, the tables are regenerated, and the architecture baseline is unchanged.
• Four computed or finite reads in moved tests were stated explicitly by hand because the codemod refuses to rewrite them (compact-spectrum, satellite-arrival-framing, scene-contract, system-view-file); each moves at the same depth, so the path text is unchanged.
• Not moved, and why:
  • site/object-shell.css and site/components/ObjectSwatchStyles.astro: a constant data-object-style identifier keeps the emitted HTML byte-identical, but the pure-move comparison renames every moved path literal in the base modules, so three prerender modules (ObjectPage.astro, object-page-contract.mts, ObjectSwatchStyles.astro) differ and L3 fails. They need a semantic-mode change or a comparison exemption for the identifier.
  • site/startup-world.mts: the server bundle keeps its relative new URL('../src/...') literal, so any depth change changes the emitted bytes.
  • Files that a pending S3 change edits (held address, loaders) and everything that imports them through a root file: moving them would close a folder cycle the baseline does not record. This includes objects.mts, world-context-plan.mts, application-world-*, scene-selection, showcase, the browsers, and the files that import a generated site/prepared-* file at the root.
  • The four tracked .d.mts stand-ins, the generated site/prepared-* files and dot-catalogue-data.mts (it reads a generated root file).

Checks

Local comparison lane against main 475bc80 (production ASSET_ORIGIN builds, merge-base tools):

• L3 built-site comparison, pure-move mode: 0 differences, semantic and layout equality both hold, pages and files unchanged.
• L2 server answers: preview 353, netlify 351 and cloudflare 348 answers identical.
• L7 counted performance guard: pass, 0 findings.

Other checks:

• pnpm check:architecture (baseline unchanged), site-architecture.mts --write tables match.
• pnpm typecheck and pnpm lint (0 errors).
• pnpm test:site: 1,788 tests, 1,756 pass, 32 skipped, 0 failures.

Follows the PR rules.