docs: simplify common CapRover workflows - #254

Summary

• Put the stable dashboard update and stable/edge switch commands on the upgrade page. Preserve the prior edge section anchors in all three locales.
• Make the installer audit optional, restore the direct One-Click image upgrade workflow, and put the dashboard rollback action first.
• Remove the duplicate Docker image example and repeated external database setup. Keep port, firewall, and TLS guidance.
• Add two short editorial rules to the existing documentation guide.

Coverage

Updated 7 English, 7 Spanish, and 7 Simplified Chinese pages. This draft covers the priority workflows above. The complete historical comparison and source audit across all 48 English pages is still outstanding.

Validation

• Documentation inventory and translation integrity checks passed.
• The documentation build passed in all three locales.
• Marketing format check and all 3 static-export tests passed. Lint reported eight image warnings and zero errors.
• Combined-site composition and HTTP smoke test passed.
• All 22 redirect unit tests and all 23 browser navigation tests passed.
• The historical compatibility audit checked 2,568 route variants and 5,872 fragment variants with zero unresolved known links.
• git diff --check passed.