feat(products): aggregate Thrivestream docs from its own repo

[coopbri]

Summary

docs.omni.dev now mirrors a product's own docs at build time instead of redirecting out to them. Thrivestream is the first product brought in; the mechanism generalizes to any product that keeps its own docs repo.

The source of truth stays with each product (docs live next to the code they document, so a product's feature PR updates its docs in the same change). This site aggregates them into one searchable portal.

Changes

• Mirror mechanism (new):
  • scripts/productDocs.config.ts — manifest of products to mirror. Adding a product is one more row. Thrivestream is pinned to a specific ref of coopbri/thrivestream-docs.
  • scripts/syncProductDocs.ts (bun run docs:sync, also wired into build) — clones each repo at its pinned ref into content/docs/products/<id>/. Rewrites upstream root-relative links to the mount path and injects canonical / sourceUrl / mirroredFrom frontmatter. Idempotent (no build-time churn); the committed mirror is the last-good fallback if a fetch fails, mirroring the existing generateCatalog approach.
• Wiring:
  • source.config.ts — frontmatter schema extended with optional canonical / mirroredFrom / sourceUrl.
  • src/routes/$.tsx — mirrored pages emit their canonical URL and "view source" link pointing home (docs.thrivestream.live / its repo), not docs.omni.dev.
  • src/routes/sitemap[.]xml.ts — mirrored pages (those carrying a canonical) are excluded to avoid duplicate URLs.
• Thrivestream: redirect stub products/thrivestream.mdx removed; 13 mirrored pages added under products/thrivestream/.
• Sidebar: removed the "Hire Us" banner.
• Build fix (fix(herald)): the committed Herald docs carried stray trailing </content> / </invoke> tags that broke the vite MDX build (fumadocs-mdx tolerated them, vite build did not). Stripped so the site builds.

Testing

• bun run build passes green.
• Pre-commit gates pass (knip, tsc --noEmit, staged Biome) — no hook bypasses.
• Sync verified idempotent: the build-time run leaves the committed mirror unchanged.

Notes

• Do not hand-edit files under a mirrored folder; edit the upstream repo and bump ref in the manifest, then bun run docs:sync.
• The Herald fix touches files from recent work (commit 55e0185); the diff is purely the trailing-tag removal.