CLI local-install applies only shared_buffers: proposed shared_preload_libraries and query tuning are dropped (UI Simple mode applies them)

Found during 4.2 pre-release testing on master @ afcba6c1 (2026-09-08).

dblab local-install probes the source and prints a proposal that includes Preload libs: pg_stat_statements (and the CLI resolves the list via probe.ResolvePreloadLibs), but the projection it applies only carries databaseConfigs.configs.shared_buffers (engine/cmd/cli/commands/localinstall/actions.go:299-302). Neither shared_preload_libraries nor the probed query-tuning parameters are written.

Result on a fresh instance installed from the CLI: /admin/config → databaseConfigs.configs = {shared_buffers: 952MB} only, and every clone runs with an empty shared_preload_libraries:

$ psql ... -c "show shared_preload_libraries"   # (empty)
$ psql ... -c "alter system set pg_stat_statements.track='all'"
ERROR:  unrecognized configuration parameter "pg_stat_statements.track"

The UI Simple-mode "Apply & start retrieval" path writes the full set (ui/packages/ce/src/api/configs/updateConfig.ts:95 writes shared_preload_libraries; the query-tuning block lands too): after a UI apply on the same instance, databaseConfigs.configs had 12 keys including shared_preload_libraries: pg_stat_statements.

So the two "Simplified Install" entry points diverge, and the CLI one silently ships a proposal it does not apply. Expected: the CLI projection writes the same databaseConfigs the UI writes (or, at minimum, shared_preload_libraries), so pg_stat_statements works in clones of CLI-installed instances.