refactor(module_loader + layers + diagnostics): selective imports (ADR-025 L2/L3)

Four files, 3 stars each -> selective.

module_loader.nu:
  config/accessor/core.nu [config-get get-config]
  config/cache/simple-cache.nu  DROPPED (dead)
  utils/                        DROPPED (dead)

layers/resolver.nu:
  taskservs/discover.nu [discover-taskservs get-taskserv-info]
  providers/discover.nu [discover-providers get-provider-info]
  clusters/discover.nu  [discover-clusters get-cluster-info]

  Note: these 3 discover.nu files live outside lib_provisioning/ (at
  core/nulib/{taskservs,providers,clusters}/). Absolute paths from
  nulib/ root preserved. Former relative paths (../../) replaced.

diagnostics/system_status.nu:
  config/accessor/core.nu [config-get]
  user/config.nu          [load-user-config]
  plugins/mod.nu          DROPPED (dead)

diagnostics/mod.nu (Layer 3 facade):
  system_status.nu ["provisioning status" "provisioning status-json"]
  health_check.nu  ["provisioning health" "provisioning health-json"]
  next_steps.nu    ["provisioning next" "provisioning phase"]
  All multi-word Nu subcommands, quoted per syntax.

Validation: all 4 nu --ide-check 50 -> 0 errors.

Refs: ADR-025

nulib/lib_provisioning/diagnostics/mod.nu

@@ -1,6 +1,9 @@
 # Diagnostics Module
 # Comprehensive system diagnostics and health monitoring
 
-export use system_status.nu *
-export use health_check.nu *
-export use next_steps.nu *
+# diagnostics/ subsystem facade — selective re-exports (ADR-025 Phase 3 Layer 3).
+# All 3 files export multi-word Nu subcommands ("provisioning status", etc.).
+
+export use system_status.nu ["provisioning status" "provisioning status-json"]
+export use health_check.nu ["provisioning health" "provisioning health-json"]
+export use next_steps.nu ["provisioning next" "provisioning phase"]

nulib/lib_provisioning/diagnostics/system_status.nu

@@ -2,9 +2,10 @@
 # Provides comprehensive system status checks for provisioning platform
 
 use std log
-use ../config/accessor.nu *
-use ../user/config.nu *
-use ../plugins/mod.nu *
+# Selective imports (ADR-025 Phase 3 Layer 2).
+# plugins/mod.nu star-import was dead — dropped.
+use lib_provisioning/config/accessor/core.nu [config-get]
+use lib_provisioning/user/config.nu [load-user-config]
 
 # Check Nushell version meets requirements
 def check-nushell-version [] {

nulib/lib_provisioning/layers/resolver.nu

@@ -3,9 +3,12 @@
 # Layered Module Resolver
 # Provides unified resolution across 3 layers: System → Workspace → Infrastructure
 
-use ../../taskservs/discover.nu *
-use ../../providers/discover.nu *
-use ../../clusters/discover.nu *
+# Selective imports (ADR-025 Phase 3 Layer 2).
+# discover.nu files live at core/nulib/{taskservs,providers,clusters}/ — outside
+# lib_provisioning/. Absolute paths from nulib/ root used.
+use taskservs/discover.nu [discover-taskservs get-taskserv-info]
+use providers/discover.nu [discover-providers get-provider-info]
+use clusters/discover.nu [discover-clusters get-cluster-info]
 
 # Resolve module path with layer information
 # Returns: {path: string, layer: string, name: string, type: string, found: bool}

nulib/lib_provisioning/module_loader.nu

@@ -4,9 +4,9 @@
 # Author: JesusPerezLorenzo
 # Date: 2025-09-29
 
-use config/accessor.nu *
-use config/cache/simple-cache.nu *
-use utils *
+# Selective imports (ADR-025 Phase 3 Layer 2).
+# config/cache/simple-cache.nu and utils/ star-imports were dead — dropped.
+use lib_provisioning/config/accessor/core.nu [config-get get-config]
 
 # Discover Nickel modules from extensions (providers, taskservs, clusters)
 export def "discover-nickel-modules" [