refactor: split util/ vs features/ + modular opt-in setupX() config

Package restructure to prepare future modularization. Three layers now:

1. fr.luc.crcore.util.* (always active)
   - common, command framework, database, message, broadcast, gui,
     placeholder

2. fr.luc.crcore.features.* (opt-in)
   - team (entities, services, repos, events, exceptions, config + GUI,
     command/Team*SubCommand)
   - player (profile, ranking, services, repos, events, exceptions)

3. fr.luc.crcore.builtin.*
   - CoreCommand + CoreReloadSubCommand (top-level routing — not a
     feature, not an util)

FQN moves (game plugins importing these need their imports updated):
- fr.luc.crcore.common.*          → fr.luc.crcore.util.common.*
- fr.luc.crcore.command.*         → fr.luc.crcore.util.command.*
- fr.luc.crcore.command.builtin.team.*
                                  → fr.luc.crcore.features.team.command.*
- fr.luc.crcore.command.builtin.CoreCommand / CoreReloadSubCommand
                                  → fr.luc.crcore.builtin.*
- fr.luc.crcore.database.*        → fr.luc.crcore.util.database.*
- fr.luc.crcore.message.*         → fr.luc.crcore.util.message.*
- fr.luc.crcore.broadcast.*       → fr.luc.crcore.util.broadcast.*
- fr.luc.crcore.gui.*             → fr.luc.crcore.util.gui.*
- fr.luc.crcore.placeholder.*     → fr.luc.crcore.util.placeholder.*
- fr.luc.crcore.team.*            → fr.luc.crcore.features.team.*
- fr.luc.crcore.player.*          → fr.luc.crcore.features.player.*

CRCoreConfig — features opt-in via fluent setup:
- setupTeams()        enables team feature
- setupPlayers()      enables player feature
- setupPlaceholders() enables PAPI integration
- setupAll()          shortcut
By default no feature is active. Game plugin must opt-in.

CRCore.enable() now conditional:
- Util services always built (messages, broadcasts, gui listener).
- Team services + repos + config built only if setupTeams().
- Player services + repos built only if setupPlayers().
- Placeholder hook registered only if setupPlaceholders() (and PAPI
  installed at runtime).
- Getters of disabled features throw IllegalStateException with a clear
  message pointing to the missing setupX() call.
- CoreCommand only registers TeamGroupSubCommand if teamService and
  teamConfig are non-null. CoreReloadSubCommand handles teamConfig=null
  (just skips that reload). /core reload always available.

Docs:
- setup.md tree fully rewritten to reflect util/+features/+builtin
  layout (~70 lines of arborescence).
- setup.md code snippet shows the three opt-in patterns (setupAll /
  granular / with options).
- decisions.md logs both decisions (restructure + modular setup).
- All .puml diagrams auto-updated to new FQNs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docs/diagrams/broadcasts-class-diagram.puml

@@ -4,7 +4,7 @@ title CR-Core — Broadcast service (class diagram)
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.broadcast" {
+package "fr.luc.crcore.util.broadcast" {
 
   enum BroadcastAudience {
     NONE
@@ -54,7 +54,7 @@ package "fr.luc.crcore.broadcast" {
   }
   CRCoreBroadcastListener ..|> "org.bukkit.event.Listener"
 
-  package "fr.luc.crcore.broadcast.impl" {
+  package "fr.luc.crcore.util.broadcast.impl" {
     class YamlBroadcastService {
       - plugin: JavaPlugin
       - messages: MessagesService
@@ -73,7 +73,7 @@ package "fr.luc.crcore.broadcast" {
 
   BroadcastService ..> BroadcastContext : consumes
   BroadcastContext --> BroadcastAudience
-  YamlBroadcastService --> "fr.luc.crcore.message.MessagesService" : reads templates
+  YamlBroadcastService --> "fr.luc.crcore.util.message.MessagesService" : reads templates
   CRCoreBroadcastListener --> BroadcastService : delegates
   CRCoreBroadcastListener ..> BroadcastContext : builds
 }

docs/diagrams/builtin-commands-diagram.puml

@@ -4,17 +4,17 @@ title CR-Core — Default /core team commands (admin / joueur)
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.command" {
+package "fr.luc.crcore.util.command" {
   abstract class BaseCommand
   abstract class SubCommand
 }
 
-package "fr.luc.crcore.command.builtin" {
+package "fr.luc.crcore.builtin" {
 
   class CoreCommand
   CoreCommand --|> BaseCommand
 
-  package "fr.luc.crcore.command.builtin.team" {
+  package "fr.luc.crcore.features.team.command" {
 
     class TeamGroupSubCommand {
       + TeamGroupSubCommand(service)

docs/diagrams/command-class-diagram.puml

@@ -4,7 +4,7 @@ title CR-Core — Command framework (class diagram, nested sub-commands)
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.command" {
+package "fr.luc.crcore.util.command" {
 
   interface Command {
     + getName(): String

docs/diagrams/database-diagram.puml

@@ -4,7 +4,7 @@ title CR-Core — Database (SQLite wrapper)
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.database" {
+package "fr.luc.crcore.util.database" {
 
   class Database {
     - connection: Connection

docs/diagrams/events-diagram.puml

@@ -8,7 +8,7 @@ package "org.bukkit.event" {
   abstract class Event
 }
 
-package "fr.luc.crcore.team.event" {
+package "fr.luc.crcore.features.team.event" {
 
   abstract class TeamEvent {
     - team: Team
@@ -57,7 +57,7 @@ package "fr.luc.crcore.team.event" {
   TeamSpawnPointChangeEvent --|> TeamEvent
 }
 
-package "fr.luc.crcore.player.event" {
+package "fr.luc.crcore.features.player.event" {
 
   abstract class PlayerProfileEvent {
     - profile: PlayerProfile

docs/diagrams/gui-class-diagram.puml

@@ -4,7 +4,7 @@ title CR-Core — GUI framework (class diagram, réutilisable)
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.gui" {
+package "fr.luc.crcore.util.gui" {
 
   abstract class AbstractInventoryGui {
     - inventory: Inventory

docs/diagrams/messages-class-diagram.puml

@@ -4,7 +4,7 @@ title CR-Core — Messages service (class diagram)
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.message" {
+package "fr.luc.crcore.util.message" {
 
   interface MessagesService {
     + get(key, placeholderPairs...): String

docs/diagrams/player-class-diagram.puml

@@ -6,7 +6,7 @@ hide empty members
 
 ' === Common abstractions ===
 
-package "fr.luc.crcore.common" {
+package "fr.luc.crcore.util.common" {
 
   interface Identifiable {
     + getId(): UUID
@@ -40,7 +40,7 @@ package "fr.luc.crcore.common" {
 
 ' === Player domain ===
 
-package "fr.luc.crcore.player" {
+package "fr.luc.crcore.features.player" {
 
   class PlayerProfile {
     - scores: Map<String, Integer>

docs/diagrams/team-class-diagram.puml

@@ -6,7 +6,7 @@ hide empty members
 
 ' === Common abstractions ===
 
-package "fr.luc.crcore.common" {
+package "fr.luc.crcore.util.common" {
 
   interface Identifiable {
     + getId(): UUID
@@ -47,7 +47,7 @@ package "fr.luc.crcore.common" {
 
 ' === Team domain ===
 
-package "fr.luc.crcore.team" {
+package "fr.luc.crcore.features.team" {
 
   enum TeamRole {
     LEADER

docs/diagrams/team-config-class-diagram.puml

@@ -4,7 +4,7 @@ title CR-Core — Team config (class diagram, cascade per-team → global → de
 skinparam classAttributeIconSize 0
 hide empty members
 
-package "fr.luc.crcore.team.config" {
+package "fr.luc.crcore.features.team.config" {
 
   class "TeamSetting<T>" as TeamSetting <<final>> {
     - key: String
@@ -60,7 +60,7 @@ package "fr.luc.crcore.team.config" {
     + getGlobalFileName(): Optional<String>
   }
 
-  package "fr.luc.crcore.team.config.impl" {
+  package "fr.luc.crcore.features.team.config.impl" {
     class YamlTeamConfigService {
       - plugin: JavaPlugin
       - teamRepository: TeamRepository
@@ -77,14 +77,14 @@ package "fr.luc.crcore.team.config" {
   TeamConfigService ..> TeamSetting : reads/writes
 }
 
-package "fr.luc.crcore.team" {
+package "fr.luc.crcore.features.team" {
   class Team {
     - settings: Map<String, Object>
     + getSettings(): Map<String, Object>
   }
 }
 
-package "fr.luc.crcore.team.config.gui" {
+package "fr.luc.crcore.features.team.config.gui" {
   abstract class AbstractSettingsGui {
     - rebuild() : peint la grille
     # {abstract} getCurrentValue(setting): T
@@ -96,14 +96,14 @@ package "fr.luc.crcore.team.config.gui" {
   class TeamSettingsGui
   GlobalSettingsGui --|> AbstractSettingsGui
   TeamSettingsGui  --|> AbstractSettingsGui
-  AbstractSettingsGui --|> "fr.luc.crcore.gui.AbstractInventoryGui"
+  AbstractSettingsGui --|> "fr.luc.crcore.util.gui.AbstractInventoryGui"
 
   GlobalSettingsGui --> TeamConfigService
   TeamSettingsGui --> TeamConfigService
   TeamSettingsGui --> Team
 }
 
-YamlTeamConfigService --> "fr.luc.crcore.team.TeamRepository" : persists per-team via save()
+YamlTeamConfigService --> "fr.luc.crcore.features.team.TeamRepository" : persists per-team via save()
 TeamConfigService ..> Team : reads/writes settings map
 
 note bottom of YamlTeamConfigService