feat(pocket-base): split hostile and passive mob spawning

design/user-stories/us-018-control-pocket-base-mob-spawning.md

@@ -1,25 +1,27 @@
 ---
 type: User Story
 title: "US-018: Control Pocket Base mob spawning"
-description: Let Pocket Base owners control natural mob spawning in their private world, with spawning disabled by default.
+description: Let Pocket Base owners control hostile and passive natural mob spawning independently in their private world, with both disabled by default.
 status: done
 ---
 
 # US-018: Control Pocket Base mob spawning
 
-As a **Pocket Base owner**, I want to enable or disable natural mob spawning in my Pocket Base so that I can choose whether the private world supports normal mob activity.
+As a **Pocket Base owner**, I want to enable or disable hostile and passive natural mob spawning independently in my Pocket Base so that I can choose which kinds of normal mob activity its private world supports.
 
 ## Acceptance criteria
 
-- [x] Natural mob spawning is disabled by default in every new Pocket Base and in existing Pocket Bases that have no saved preference.
-- [x] A Pocket Base owner can use `/basesettings pocket mobs enable|disable` to control natural mob spawning in their own Pocket Base.
-- [x] The setting controls both hostile and passive natural spawning only in the owner's Pocket Base.
-- [x] The command is unavailable until Pocket Base I is unlocked.
-- [x] The command and its modes are offered through contextual autocomplete.
-- [x] `/basesettings status` displays the current Pocket Base mob-spawning setting.
-- [x] The preference persists across restarts and is reapplied when the Pocket Base world loads.
-- [x] Disabling natural spawning does not remove existing mobs or prevent explicitly spawned or summoned mobs.
-- [x] Persistence or world-application failures produce a clear failure message without reporting a successful change.
+- [x] Hostile and passive natural mob spawning are both disabled by default in every new Pocket Base and in existing Pocket Bases that have no saved preference.
+- [x] A Pocket Base owner can use `/basesettings pocket mobs hostile enable|disable` to control hostile natural mob spawning in their own Pocket Base.
+- [x] A Pocket Base owner can use `/basesettings pocket mobs passive enable|disable` to control passive natural mob spawning in their own Pocket Base.
+- [x] Changing one mob category does not change the other category.
+- [x] The commands are unavailable until Pocket Base I is unlocked.
+- [x] The commands, categories, and modes are offered through contextual autocomplete.
+- [x] `/basesettings status` displays the current hostile and passive Pocket Base mob-spawning settings.
+- [x] Both preferences persist across restarts and are reapplied when the Pocket Base world loads.
+- [x] Existing saved `mob-spawning-enabled` values migrate to both category preferences, preserving prior behavior.
+- [x] Disabling either natural-spawning category does not remove existing mobs or prevent explicitly spawned or summoned mobs.
+- [x] Persistence or world-application failures produce a clear failure message, restore both prior world flags, and do not report a successful change.
 
 ## Related