fix: write MariaDB's startup spelling for time_zone into the option file

mariadbd has no time_zone startup option — the name only exists for SET — so
the resolved parameter group aborted the server while it parsed defaults, before
it opened the datadir. No pidfile was ever written and the reconciler failed
every instance at the 20-minute engine-health deadline.

ParameterSpec gains an option-file spelling, used only when rendering the
include. time_zone is the one setting that needs it, as default_time_zone, which
resolves @@global.time_zone to the same value. The customer-facing name is
unchanged: the API still reports time_zone and a live apply still issues
SET GLOBAL time_zone. Names read back out of a generated file return to the
catalog's namespace first, so a startup spelling cannot read as an unknown name
and report a pending restart nothing could clear.

setup.sh now feeds the catalog's resolved defaults to the image's own mariadbd
at build time, so a name the server refuses fails the build rather than every
instance built from it.

scripts/images/rds-mariadb/default-parameters.cnf

@@ -0,0 +1,56 @@
+[mysqld]
+# Resolved parameter group, written by rds-agent.
+autocommit = 'on'
+character_set_server = 'utf8mb4'
+collation_server = 'utf8mb4_general_ci'
+connect_timeout = '10'
+event_scheduler = 'off'
+general_log = 'off'
+group_concat_max_len = '1048576'
+idle_transaction_timeout = '0'
+innodb_adaptive_hash_index = 'off'
+innodb_autoinc_lock_mode = '1'
+innodb_buffer_pool_size = '805306368'
+innodb_file_per_table = 'on'
+innodb_flush_log_at_trx_commit = '1'
+innodb_flush_method = 'o_direct'
+innodb_flush_neighbors = '1'
+innodb_io_capacity = '200'
+innodb_io_capacity_max = '2000'
+innodb_lock_wait_timeout = '50'
+innodb_log_file_size = '100663296'
+innodb_max_dirty_pages_pct = '90'
+innodb_purge_threads = '4'
+innodb_read_io_threads = '4'
+innodb_stats_persistent = 'on'
+innodb_strict_mode = 'on'
+innodb_write_io_threads = '4'
+interactive_timeout = '28800'
+join_buffer_size = '262144'
+key_buffer_size = '134217728'
+lock_wait_timeout = '86400'
+log_output = 'file'
+log_queries_not_using_indexes = 'off'
+log_warnings = '2'
+long_query_time = '10'
+max_allowed_packet = '16777216'
+max_connect_errors = '100'
+max_connections = '85'
+max_heap_table_size = '16777216'
+max_prepared_stmt_count = '16382'
+max_statement_time = '0'
+net_read_timeout = '30'
+net_write_timeout = '60'
+performance_schema = 'off'
+read_buffer_size = '131072'
+read_rnd_buffer_size = '262144'
+slow_query_log = 'off'
+sort_buffer_size = '2097152'
+sql_mode = 'STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_ENGINE_SUBSTITUTION'
+table_definition_cache = '400'
+table_open_cache = '2000'
+thread_cache_size = '256'
+default_time_zone = 'SYSTEM'
+tmp_table_size = '16777216'
+transaction_isolation = 'repeatable-read'
+wait_timeout = '28800'

scripts/images/rds-mariadb/manifest.conf

@@ -36,6 +36,7 @@ scripts/images/common/mulga-mgmt-net.initd:/etc/init.d/mulga-mgmt-net \
 scripts/images/common/mulga-mgmt-net-routes.initd:/etc/init.d/mulga-mgmt-net-routes \
 scripts/images/common/mulga-mgmt-net.sh:/usr/local/sbin/mulga-mgmt-net \
 scripts/images/rds-mariadb/zz-rds-include.cnf:/etc/my.cnf.d/zz-rds-include.cnf \
+scripts/images/rds-mariadb/default-parameters.cnf:/usr/local/share/spinifex-rds/default-parameters.cnf \
 scripts/images/rds-mariadb/mariadb.confd:/etc/conf.d/mariadb"
 
 # Each service's own depend() asserts the ordering; this lists it to match.

scripts/images/rds-mariadb/setup.sh

@@ -62,6 +62,29 @@ if grep -rEq '^[[:space:]]*skip[-_]networking' /etc/my.cnf /etc/my.cnf.d; then
     exit 1
 fi
 
+# The resolved defaults checked against this image's own mariadbd. A name the
+# server refuses at startup is not a rejected setting: it aborts the boot with the
+# generated file already on the data volume. cmd/rds-agent keeps this file in step.
+#
+# --verbose --help parses the option files and exits without touching a datadir,
+# so it is the whole check. defaults-extra-file rather than the include directory,
+# which stays empty in the image; it must be the first option mariadbd sees.
+default_params=/usr/local/share/spinifex-rds/default-parameters.cnf
+if [ ! -f "${default_params}" ]; then
+    echo "[rds-mariadb-setup] the catalog's default parameter set was not delivered to ${default_params}"
+    exit 1
+fi
+if ! mariadbd --defaults-extra-file="${default_params}" --user=mysql --verbose --help \
+    >/dev/null 2>/tmp/rds-defaults.err; then
+    echo "[rds-mariadb-setup] mariadbd refuses the catalog's default parameter set"
+    cat /tmp/rds-defaults.err
+    exit 1
+fi
+# Build-time only: nothing at runtime reads it, and an include the server could
+# find twice is a way for a stale copy to shadow the customer's own set.
+rm -f /tmp/rds-defaults.err "${default_params}"
+rmdir /usr/local/share/spinifex-rds 2>/dev/null || true
+
 # The packaged service starts on a warning when the datadir is empty, so the
 # dependency is what keeps it off an unbootstrapped volume. Asserted here, since
 # an image whose engine can come up beside a failed bootstrap is the one failure