chore(ci): publish latest from main and retire the edge tag (#711)

* fix(docs): update versioning strategy and tag policies for Docker images

* fix(docs): clarify versioning strategy in environment configuration
fix(docker): update docker-push script to remove local latest tag handling

* fix(docs): clarify VERSION variable usage in Docker push script

.env.example

@@ -7,8 +7,10 @@
 # Image version (only used by docker-compose.images.yaml — the pull-based stack)
 # ──────────────────────────────────────────────
 # Which published image tag to pull for api/dashboard/jobs.
-#   - Pin to a release (e.g. 1.4.2) in production so a new release never auto-breaks you.
-#   - "latest" = newest stable release.  "edge" = bleeding edge (last main build).
+#   - "latest" (below) = freshest main build; it MOVES on every merge to main (rolling, may
+#     include unreleased code), so a later `pull` can shift you to a newer build unannounced.
+#   - For production, PIN an exact release (e.g. 1.4.2) so a merge to main never auto-breaks you.
+#     "1.4.2" / "1.4" / "1" are immutable, published on a v* git tag.
 # Rollback = set this back to the previous version, then `... pull && up -d`.
 CIO_VERSION=latest