The update center previously surfaced stable Docker Hub candidates but
left dev and branch-tag rollouts stranded in SSH and Helm commands.
This adds a repo-native manual Docker tag entrypoint in Settings so
operators can deploy dev, branch, temporary, or sha tags through the
existing helper flow without changing the backend deploy contract.
Constraint: Keep the existing helper API and digest-aware Helm contract unchanged
Constraint: Preserve stable Docker Hub candidate discovery for default reminders
Rejected: Expand automatic Docker Hub discovery to all branch tags | would blur stable release reminders with operator-only rollout targets
Confidence: high
Scope-risk: narrow
Reversibility: clean
Directive: Keep automatic candidate detection stable-first; manual tag deploy is the escape hatch for non-stable tags
Tested: update-center focused vitest suite; typecheck; build:web; docs:build; repo:drift-check
Not-tested: Full npm test remains red due to unrelated tmp/sub2api frontend suites and an existing firstByteTimeout unhandled error
cita-777
87fb5149e6