1.6.162: gate Host Add Container and translate Secrets desktop headers

[chen21019]

Changes

• Gate Host-detail Add Container using the current project's loaded container POST capability and preserve the selected Host query.
• Translate the four Secrets desktop headers with existing generic keys; retain all legacy column/sort/search/width mappings.
• Prepare 1.6.162 with version-only lock metadata and scoped release documentation. No vendor/backend/route/workflow/dependency-resolution changes.

Validation

• Primary reviewer Chrome 153 source results: Secrets 2/2; Host 8/8 (four new plus four adjacent existing cases).
• New candidate real-template/table rendering checks: 2/2 PASS in Chrome 153, including Host query binding and English/Traditional Chinese desktop headers. Assertions target the actual fixed-header row, not its geometry placeholder.
• Syntax, exact reviewed five-file hashes, staged allowlist, diff whitespace, version-only lock comparison and public-document checks passed.
• Official CI is pending; one existing Validate Web Console dispatch will target this exact branch. No merge or tag is requested.

Boundaries

Desktop-only. Mobile Secrets data-title labels keep their legacy displayName mechanism. No all-language layout, server write authorization, packaged browser acceptance or full lifecycle/matrix completion is claimed. Earlier HOLD receipts remain HOLD; the broader matrix remains INCOMPLETE.