chore: bump Ghost to 6.54.1; 6.53.0:2 → 6.54.1:0

[helix-nine]

Summary

Bumps Ghost from 6.53.0 to 6.54.1 (ghost:6.54.1-alpine), and the StartOS version from 6.53.0:2 to 6.54.1:0.

MySQL stays pinned at mysql:8.4.10 — per UPDATING.md, it moves only when we intentionally change the database line, and 8.4 is what this Ghost release targets.

@start9labs/start-sdk is already at 2.0.9, the current npm latest, so no SDK bump rode along. No npm state changed (no git dependencies in this package; npm ci reproduces the committed lock).

Upstream highlights (6.53.0 → 6.54.1)

• 🔒 Filename generation for uploads made more secure, performant, and resilient to filesystem limits.
• ✨ Inline editor for routes.yaml and redirects.yaml in the admin panel.
• ✨ Member labels, complimentary member subscriptions, and member.avatar_image gravatars for themes.
• ✨ Config option for a custom adapter install location; canary (v4) schema/API endpoint.
• 🐛 Several members CSV import fixes (labels containing commas, formula-escape characters, uneven columns), sitemap now includes posts with a self-referential canonical URL, dark-mode loader background, YouTube bookmark metadata.
• 🐛 6.54.1 patch: fixed settings preview interaction regressions introduced in 6.54.0.

Full notes: v6.54.0 · v6.54.1

Verification

• ghost:6.54.1-alpine confirmed published on Docker Hub with both amd64 and arm64 manifests (pushed 2026-07-27).
• 6.54.1:0 is free — the registry currently has 6.53.0:2 as latest.
• npm run check (tsc) green.
• No migration needed: the release carries no StartOS-side state change, so current.ts was edited in place.

Docs

README.md and instructions.md carry no version numbers and describe no behavior this release changes, so neither needed an update. The new admin-side routes.yaml/redirects.yaml editor is entirely within Ghost's own admin panel.