docs(dragon-q8b): expand M.2 E Key card compatibility

[tzz-radxa]

Description of changes

• Add a Tested Platform column to the Dragon Q8B M.2 E Key compatibility table.
• Mark the existing verified cards as tested on Windows and Linux.
• Add MediaTek MT7921/MT7922, Realtek RTL8852CE, Intel BE200/AX210/8260 as Linux-tested models.
• Clarify that the Realtek/Intel and MediaTek MT7925/MT7927 driver notes apply only to Q8B Windows testing.
• Keep the Chinese and English pages synchronized.

The compatibility updates are based on internal hardware validation results.

Agent-doc checklist

• I ran scripts/agent-doc-lint.sh on changed doc files.
• Changed page docs are not empty, include front matter, and have an H1 heading.
• Code fences in changed docs include language labels.
• I removed TODO/TBD/XXX placeholders from non-template docs.
• I reviewed whether docs/ and i18n/en/... need to be synced.
• I did not introduce new docs/i18n path drift, or I updated .github/agent-doc-drift-baseline.md intentionally.
• I did not introduce new translation placeholders, or I updated .github/agent-doc-translation-baseline.md and .github/agent-doc-translation-backlog.md intentionally.

Validation notes

• pre-commit: passed for both changed files
• additional checks: agent-doc-lint.sh, agent-doc-drift-guard.sh, agent-doc-translation-guard.sh, product-index check, and local PR scope guard passed