docs(e25): move Radxa E25 from ROCK 3 to the E series

[tzz-radxa]

Summary

• Move the Radxa E25 tutorial set from rock3/e25 to e/e25, Chinese and English mirror together, using git mv so the file history is preserved.
• Update every in-repo reference to the new path:
  • docs/productlist.md and the English counterpart
  • docs/Home.md and the English counterpart (E series card added for E25)
  • docs/e/README.md and the English counterpart (E25 row added to the product table)
  • .github/CODEOWNERS (e/e25/os-config/rsetup.md)
• Add static/home/product-pictures/e25.webp (660x300, same aspect as the other E series cards) and regenerate static/agent/products.json, which now exposes radxa-e25 for both locales.

Why

E25 is a network computing product and belongs to the E series docs tree; it was previously published under ROCK 3, which made it hard to find next to E20C/E24C/E52C/E54C.

Compatibility

• Existing /rock3/e25/* URLs keep working: the companion docs-template PR adds client redirects so the old paths resolve to /e/e25/*.
• The changed file count is high only because the whole product subtree moves in one step; no unrelated fixes are mixed in.

Verification

• python3 scripts/github_pr_guard.py check --base upstream-docs/main returns reasons: [] (bilingual pairs complete, single product scope).
• python3 scripts/generate-agent-product-index.py regenerated the agent product index, and docs/e/README.md lists E25 next to the other E series boards.

Notes

• The E series table describes E25 as RK3568, matching docs/software-support-matrix/rockchip.md and the rk3568_e25 image name in docs/rock3/images.md. docs/productlist.md still described E25 as RK3528A before this change; that wording is pre-existing and left untouched here so it can be confirmed separately.