⚡ Speed up go toolchain container startup ⚡

Pre-set service-discovery vars in a Docker env file so the entrypoint's
${VAR:-$(function)} expansions skip all seven __find_* subprocess forks on
every container start. Also suppress the startup banner and health loop
since this image has no long-running daemon.
Fix overly-broad `env/` gitignore pattern that silently swallowed
rootfs/…/docker/env/ and any other env directory in the tree. Replace with
the root-anchored `/env/` and `src/env/` which only match the Python venv
paths originally intended.
- rootfs/usr/local/etc/docker/env/go.sh: new — pre-sets PHP_INI_DIR,
PHP_BIN_DIR, HTTPD_CONFIG_FILE, NGINX_CONFIG_FILE, MYSQL_CONFIG_FILE,
PGSQL_CONFIG_FILE, MONGODB_CONFIG_FILE to "none"; sets
ENTRYPOINT_MESSAGE=no and HEALTH_ENABLED=no
- .gitignore: replace bare `env/` with `/env/` and `src/env/` to avoid
matching Docker env config directories inside rootfs

.gitignore
rootfs/usr/local/etc/docker/env/

.gitignore

@@ -189,7 +189,9 @@ __pycache__/
 .eggs/
 .venv/
 venv/
-env/
+# bare 'env/' would swallow rootfs/…/docker/env/ — use anchored patterns instead
+/env/
+src/env/
 
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