feat: configurable broadcasts + /core reload

New fr.luc.crcore.broadcast module:
- BroadcastAudience enum (NONE, LEADER, TEAM, ADMIN, ALL).
- BroadcastContext (fluent: team + involvedPlayerId + placeholders).
- BroadcastService interface + YamlBroadcastService impl.
- CRCoreBroadcastListener (Bukkit listener) wires the 12 native events
  (9 team + 3 player) to broadcasts.broadcast(eventKey, ctx).

Same single-per-plugin file pattern as messages:
<plugin-dataFolder>/<plugin-name-lowercase>-broadcasts.yml. Defaults
bundled at resources/crcore-broadcasts.yml, copied on first boot (game
plugin's own resource of the same name takes priority as the template).
In-memory fallback so new CR-Core keys work without admin edit.

Routes (who) vs templates (what) are separated: broadcasts.yml lists
audiences per eventKey, messages.yml contains the templates under keys
<eventKey>.broadcast. Admin can change either independently.

12 new *.broadcast keys added to crcore-messages.yml with sensible
French defaults and color codes. Listener injects standard placeholders
(name, team_name, tag, color, visibility, player, new_leader,
old/new_value, etc.).

ADMIN audience resolved via crcore.broadcast.admin permission. Multi-
audiences via YAML list (e.g., [TEAM, ADMIN]); union of resolved
players, no duplicate.

New /core reload subcommand (permission crcore.reload) hot-reloads
both messages and broadcasts from disk without restart.

CRCore: protected buildBroadcastService() override point, getter
broadcasts(), wire of CRCoreBroadcastListener at enable(). CoreCommand
constructor extended to take BroadcastService, registers the reload
subcommand.

Docs/features.md: new section 9 "Service de broadcasts". docs/setup.md:
updated to mention both YAML files. decisions.md logs the routes-vs-
templates split, the audience model, and the reload semantics.
New diagram broadcasts-class-diagram.puml. README updated.

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

docs/diagrams/broadcasts-class-diagram.puml

@@ -0,0 +1,102 @@
+@startuml broadcasts-class-diagram
+title CR-Core — Broadcast service (class diagram)
+
+skinparam classAttributeIconSize 0
+hide empty members
+
+package "fr.luc.crcore.broadcast" {
+
+  enum BroadcastAudience {
+    NONE
+    LEADER
+    TEAM
+    ADMIN
+    ALL
+  }
+
+  class BroadcastContext {
+    - team: Team
+    - involvedPlayerId: UUID
+    - placeholders: Map<String, String>
+    --
+    + {static} of(team): BroadcastContext
+    + {static} empty(): BroadcastContext
+    + involving(playerId): BroadcastContext
+    + with(key, value): BroadcastContext
+    + getTeam(): Optional<Team>
+    + getInvolvedPlayerId(): Optional<UUID>
+    + getPlaceholders(): Map<String, String>
+    + toPlaceholderPairs(): Object[]
+  }
+
+  interface BroadcastService {
+    + broadcast(eventKey, context): void
+    + getAudiences(eventKey): List<BroadcastAudience>
+    + reload(): void
+  }
+
+  class CRCoreBroadcastListener {
+    - broadcasts: BroadcastService
+    + registerOn(plugin: JavaPlugin): void
+    --
+    @ onTeamCreate(TeamCreateEvent)
+    @ onTeamDissolve(TeamDissolveEvent)
+    @ onTeamMemberAdd(TeamMemberAddEvent)
+    @ onTeamMemberRemove(TeamMemberRemoveEvent)
+    @ onPlayerJoinTeam(PlayerJoinTeamEvent)
+    @ onLeadershipTransfer(TeamLeadershipTransferEvent)
+    @ onVisibilityChange(TeamVisibilityChangeEvent)
+    @ onTeamScoreChange(TeamScoreChangeEvent)
+    @ onTeamSpawnChange(TeamSpawnPointChangeEvent)
+    @ onProfileCreate(PlayerProfileCreateEvent)
+    @ onProfileDelete(PlayerProfileDeleteEvent)
+    @ onPlayerScoreChange(PlayerScoreChangeEvent)
+  }
+  CRCoreBroadcastListener ..|> "org.bukkit.event.Listener"
+
+  package "fr.luc.crcore.broadcast.impl" {
+    class YamlBroadcastService {
+      - plugin: JavaPlugin
+      - messages: MessagesService
+      - defaults: Map<String, List<BroadcastAudience>>
+      - audiences: Map<String, List<BroadcastAudience>>
+      - userFile: File
+      --
+      + YamlBroadcastService(plugin, messages)
+      - loadDefaultsFromResource(): void
+      - ensureUserFile(): void
+      - rebuildEffectiveAudiences(): void
+      - resolveRecipients(list, ctx): Set<Player>
+    }
+    YamlBroadcastService ..|> BroadcastService
+  }
+
+  BroadcastService ..> BroadcastContext : consumes
+  BroadcastContext --> BroadcastAudience
+  YamlBroadcastService --> "fr.luc.crcore.message.MessagesService" : reads templates
+  CRCoreBroadcastListener --> BroadcastService : delegates
+  CRCoreBroadcastListener ..> BroadcastContext : builds
+}
+
+package "fr.luc.crcore" {
+  class CRCore {
+    + broadcasts(): BroadcastService
+    # buildBroadcastService(messages): BroadcastService
+  }
+  CRCore "1" *-- "1" BroadcastService : owns
+  CRCore ..> CRCoreBroadcastListener : registers
+}
+
+note bottom of YamlBroadcastService
+  Modèle "un seul fichier par plugin" :
+
+  Sources en mémoire :
+    1. crcore-broadcasts.yml         ← jar (fallback)
+    2. <plugin>-broadcasts.yml       ← dataFolder (édité par l'admin)
+
+  Séparation routes / templates :
+    - Routes = ce fichier (qui reçoit quoi)
+    - Templates = MessagesService (clés <event>.broadcast)
+end note
+
+@enduml