mr0: add CONFIG_SPECS registry; derive defaults, CLI targets, print, validation

Introduce src/lib/config.spec.source.sh: CONFIG_SPECS, a single '|'-delimited
config-field registry (name|default|has_default|cli_overridable|validation|
print_kind), using the same spec idiom as ACTION_SPECS / TEMPLATE_RENDER_FIELD_SPECS.
This replaces the parallel, hand-maintained config-knowledge lists that caused the
TARBALL_INCLUDE default-drift bug (fixed in 7r0).

Derived consumers (behaviour byte-identical):
- apply_config_defaults: loops the registry applying VAR="${VAR:-default}" for
  has_default=yes scalars; arrays keep their declare -p guards.
- CLI_CONFIG_OVERRIDE_TARGETS: built from cli_overridable=yes (verified to match
  CLI_OPTION_SPEC's config= targets exactly).
- print_config: emits in registry order dispatching on print_kind.
- validate_common_config: required set + per-field rule come from the registry via
  config_spec_validation + validate_config_field_required/_kind; two-phase order and
  historical reporting order preserved.

log_configured_action and the dry-run plan are not yet converted (bespoke prose /
intermixed computed values). shellcheck: TARBALL_SUFFIX lost its visible literal
assignment, annotated at the archive use site.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/tests/cli.sh b/tests/cli.sh
index c8cbd36..ca5d170 100755
--- a/tests/cli.sh
+++ b/tests/cli.sh
@@ -2486,6 +2486,11 @@ test_config_validators_fail_fast_without_errexit() {
     local output
     local -i status=0
 
+    # validate_common_config derives its required set and per-field rules from
+    # CONFIG_SPECS (task mr0), so the registry module must be sourced alongside
+    # the validators when exercising it in isolation.
+    # shellcheck source=src/lib/config.spec.source.sh
+    source "$TEST_REPO_ROOT/src/lib/config.spec.source.sh"
     # shellcheck source=src/lib/config.validate.source.sh
     source "$TEST_REPO_ROOT/src/lib/config.validate.source.sh"