chore(deploy): upgrade the docs deploy to dash 4 and repoint at zoolutions

[mhenrixon]

Summary

Fleet-wide follow-up to zoolutions/docs-kit#74 (docs-kit 1.1.0): the docs site deploys with dash 4 and the repo's live references point at zoolutions/phlex-forms.

• docs/config/deploy.yml: minimum_version: 4.0.0, retain_containers: 2, error_pages_path: public (+ public/502|503|504.html), and the dash-proxy per-app block — compress, cache { enabled, max_ttl: 300 }, security headers, intercept_errors [502,503,504], exclude_metrics_paths [/up]
• docs/.kamal/secrets → docs/.dash/secrets with DASH_REGISTRY_PASSWORD (docs-kit's reusable workflow exports both names — no flag day)
• docs/.dockerignore excludes /.dash/ next to /.kamal/
• Live links / badges / gemspec URLs → zoolutions/phlex-forms; CHANGELOG / UPGRADING / blog history untouched (GitHub redirects the old owner)

Deliberately not set: proxy.run (host-wide, shared by every docs site on the host) and rate_limit / deny_ips / client_ip (need the tunnel's address as trusted_proxies).

Test plan

• dash config (dash main @ 4.0.0) accepts the new deploy.yml
• CI green
• After merge: run Deploy docs (workflow_dispatch) — expect the dash doctor report, the one-off kamal-proxy → dash-proxy rename if this is the first dash 4 deploy on the host (short outage), then a healthy phlex-forms.zoolutions.llc

https://claude.ai/code/session_01SdEc37DFCkYzwpQpadu9My

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Summary by cubic

Upgrades the docs deploy from Kamal to dash 4 and repoints live references from mhenrixon/phlex-forms to zoolutions/phlex-forms. The first dash 4 deploy on the shared host renames kamal-proxy to dash-proxy with a short outage that whichever site deploys first pays.

Migration

• Requires dash >= 4.0.0 via minimum_version, keeps 2 old containers, and serves public/502|503|504.html during deploy gaps.
• Enables compression, a response cache with a 300s TTL, response security headers, and excludes /up from metrics.
• Moves secrets from docs/.kamal/secrets to docs/.dash/secrets with DASH_REGISTRY_PASSWORD; the workflow exports both names, so there's no flag day.
• .dockerignore excludes /.dash/; README references point at zoolutions/phlex-forms while changelog and upgrade history stay untouched.

^{Written for commit e793cab. Summary will update on new commits.}