Remove non-functional Joomla LDAP integration

- Disabled LDAP feature flag (set to false by default, with comment)
- Removed ldapautocreate plugin (PHP + XML)
- Deleted LDAP helper tasks (01_ldap_files.yml, 05_ldap.yml, 07_diagnose.yml)
- Deleted LDAP CLI helper scripts (cli.php, diagnose.php, plugins.php, auth-trace.php)
- Removed LDAP configuration variables from vars/main.yml
- Removed LDAP environment variables from env.j2
- Removed LDAP-specific mounts from docker-compose.yml.j2
- Dropped php-ldap installation from Dockerfile
- Renamed task files for consistent numbering (02->01_install, 03->02_debug, 04->03_patch, 06->04_assert)

Reason: LDAP integration was removed because it was not functional.

Conversation: https://chatgpt.com/share/68b09373-7aa8-800f-8f2c-11e27123bad1

roles/web-app-joomla/templates/Dockerfile.j2

@@ -1,15 +1 @@
 FROM {{ JOOMLA_IMAGE }}:{{ JOOMLA_VERSION }}
-{% if JOOMLA_LDAP_ENABLED %}
-ENV DEBIAN_FRONTEND=noninteractive
-RUN set -eux; \
-    apt-get update; \
-    PHPV="$(php -r 'echo PHP_MAJOR_VERSION.".".PHP_MINOR_VERSION;')" || PHPV=""; \
-    apt-get install -y --no-install-recommends "php${PHPV}-ldap" \
-    || ( \
-      apt-get install -y --no-install-recommends libldap2-dev libsasl2-dev pkg-config; \
-      docker-php-ext-configure ldap --with-ldap=/usr --with-ldap-sasl=/usr \
-        || docker-php-ext-configure ldap --with-ldap=/usr; \
-      docker-php-ext-install -j"$(nproc)" ldap \
-    ); \
-    rm -rf /var/lib/apt/lists/*
-{% endif %}