docs: say the 2.x image is not published; show the local build (audit M6)

README, guide and deploy/docker-compose.yml pinned
ghcr.io/mixeme/selfpost:2.4.1, which does not exist: ghcr.io holds 1.0.0
and 1.3.0 only. The owner decided (2026-10-12) that old tags and images
stay untouched and the pin points forward, made true by the next
publication. Until then:

- README Quick start and guide Fixed image tag say the 2.x line is not on
  ghcr.io and show `docker build ... --build-arg VERSION=2.4.1 -t
  ghcr.io/mixeme/selfpost:2.4.1 .`; with the image present locally,
  docker run and Compose (pull_policy missing) use it without pulling.
- compose header says the same in two lines.
- development.md release steps: bump the version in those notes at each
  cut, remove them at the first publication of the line.
- CHANGELOG [Unreleased], audit plan line ticked, roadmap 4/61.

Documents only; no test reads the pin.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/development.md

@@ -280,7 +280,11 @@ they are.)
 
 1. Close `[Unreleased]` in [CHANGELOG.md](../CHANGELOG.md) and bump the pinned
    tag in [deploy/docker-compose.yml](../deploy/docker-compose.yml) (and any
-   local-trial image references) in the **same** release commit.
+   local-trial image references) in the **same** release commit. While no
+   image of the current line is published, README, guide § Fixed image tag
+   and the compose file's header say so and show the local build under the
+   pinned name; bump the version there too. The first publication of the
+   line removes those notes.
 2. Create and push git tag `vX.Y.Z` on that commit.
 3. Publish the GitHub Release for `vX.Y.Z` (not a draft).
 4. Workflow [release.yml](../.github/workflows/release.yml) builds, e2e-gates,