feat: SQLite persistence, default /core commands, Bukkit events, bootstrap

CRCore bootstrap class: one-line setup for game plugins (new CRCore(this).enable()).
Wires SQLite, services with event firing, and the /core command tree.

SQLite layer (fr.luc.crcore.database): Database wrapper exposing execute/update/
queryOne/query plus a fluent TableBuilder. ColumnType enum, RowMapper interface,
DatabaseException. Game plugins create their own tables in 2 lines via
db.table("foo").ifNotExists().column(...).create().

Repositories: SqliteTeamRepository and SqlitePlayerProfileRepository extend their
InMemory counterparts (write-through cache). 5 internal tables prefixed crcore_.

Command framework refactored for nested sub-commands: subcommand storage moved
from BaseCommand to AbstractCommand, recursive dispatch() and tabComplete(),
replaceSubCommand() for plugin overrides.

Default /core team commands (13 leaf sub-commands): create, delete, add, remove,
join, leave, info, list, transfer, visibility, score, top, setspawn. Each in its
own class under fr.luc.crcore.command.builtin.team, fully substitutable.

Bukkit events: 9 team events (Create/Dissolve/MemberAdd/MemberRemove/PlayerJoin/
LeadershipTransfer/VisibilityChange/ScoreChange/SpawnPointChange) + 3 player
events (ProfileCreate/Delete/ScoreChange). All post-only, non-cancellable.
BukkitEventFiringTeamServiceImpl and BukkitEventFiringPlayerProfileServiceImpl
override the on* hooks to call Bukkit.getPluginManager().callEvent.

JavaDoc on all new public classes and key existing ones. docs/, GEMINI.md and
PUML diagrams synced: new sections (built-in commands, events, database,
bootstrap), 4 new diagrams (builtin-commands, events, database, bootstrap-
sequence), and 7 new architecture decisions logged.

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

docs/diagrams/bootstrap-sequence.puml

@@ -0,0 +1,62 @@
+@startuml bootstrap-sequence
+title CR-Core — Bootstrap from a game plugin (onEnable)
+
+participant "MyGamePlugin\nextends JavaPlugin" as Plugin
+participant "CRCore" as Core
+participant "Database" as DB
+participant "SqliteTeamRepository" as TeamRepo
+participant "SqlitePlayerProfileRepository" as PlayerRepo
+participant "BukkitEventFiringTeamServiceImpl" as TeamSvc
+participant "BukkitEventFiringPlayerProfileServiceImpl" as PlayerSvc
+participant "CoreCommand\n(/core)" as Cmd
+participant "Bukkit" as Bukkit
+
+Plugin -> Core : new CRCore(this)
+activate Core
+
+Plugin -> Core : enable()
+
+Core -> DB : new Database(<dataFolder>/crcore.db)
+activate DB
+DB -> DB : ensure parent dir + PRAGMA foreign_keys
+DB --> Core
+deactivate DB
+
+Core -> TeamRepo : new SqliteTeamRepository(db)
+activate TeamRepo
+TeamRepo -> DB : ensureSchema() — crcore_teams + crcore_team_members + crcore_team_scores
+TeamRepo -> DB : loadAll() — SELECT pour ré-hydrater le cache mémoire
+TeamRepo --> Core
+deactivate TeamRepo
+
+Core -> PlayerRepo : new SqlitePlayerProfileRepository(db)
+activate PlayerRepo
+PlayerRepo -> DB : ensureSchema() — crcore_player_profiles + crcore_player_scores
+PlayerRepo -> DB : loadAll()
+PlayerRepo --> Core
+deactivate PlayerRepo
+
+Core -> TeamSvc : buildTeamService(teamRepo)
+Core -> PlayerSvc : buildPlayerProfileService(playerRepo)
+
+Core -> Cmd : new CoreCommand(teamSvc, playerSvc)
+activate Cmd
+Cmd -> Cmd : registerDefaults() — TeamGroupSubCommand avec 13 leaf sub-cmds
+Cmd --> Core
+deactivate Cmd
+
+Core -> Bukkit : plugin.getCommand("core").setExecutor(cmd)
+Core -> Bukkit : .setTabCompleter(cmd)
+
+Core --> Plugin : this (chainable)
+deactivate Core
+
+note over Plugin
+  À ce stade :
+  - /core team create/delete/add/... fonctionnel
+  - SQLite persiste team + player + leurs scores
+  - Évènements Bukkit sont tirés sur chaque opération
+  - Le plugin de jeu peut listen avec @EventHandler
+end note
+
+@enduml