feat: implement phases 3-5 of Arma 3 UX enhancement plan

Phase 3 - Mod display names + split-pane selector:
- Parse mod.cpp/meta.cpp for display_name and workshop_id
- Rewrite ModList as two-pane available/selected interface

Phase 4 - Player kick/ban from Players tab:
- Add get_by_slot() to PlayerRepository
- Add get_rcon_client() class method to ThreadRegistry
- Add /players/{slot_id}/kick and /ban endpoints
- Rewrite PlayerTable with kick/ban modals and ban presets

Phase 5 - Historical log file browser:
- Add list_log_files() and get_log_file_path() to RPTParser
- Add logfiles_router with GET/download/DELETE endpoints
- Update LogViewer with collapsible log files section (download + delete)

backend/core/servers/players_router.py

@@ -5,18 +5,28 @@ import logging
 from typing import Annotated
 
 from fastapi import APIRouter, Depends
+from pydantic import BaseModel
 from sqlalchemy.engine import Connection
 
 from core.dal.player_repository import PlayerRepository
 from core.servers.service import ServerService
 from database import get_db
-from dependencies import get_current_user
+from dependencies import get_current_user, require_admin
 
 logger = logging.getLogger(__name__)
 
 router = APIRouter(prefix="/servers/{server_id}/players", tags=["players"])
 
 
+class KickRequest(BaseModel):
+    reason: str = "Kicked by admin"
+
+
+class BanFromPlayerRequest(BaseModel):
+    reason: str = "Banned by admin"
+    duration_minutes: int | None = None
+
+
 def _ok(data):
     return {"success": True, "data": data, "error": None}
 
@@ -54,4 +64,31 @@ def player_history(
     total, rows = player_repo.get_history(
         server_id=server_id, limit=limit, offset=offset, search=search,
     )
-    return _ok({"total": total, "items": rows})
+    return _ok({"total": total, "items": rows})
+
+
+@router.post("/{slot_id}/kick")
+def kick_player(
+    server_id: int,
+    slot_id: int,
+    body: KickRequest,
+    db: Annotated[Connection, Depends(get_db)],
+    _admin: Annotated[dict, Depends(require_admin)],
+) -> dict:
+    ServerService(db).kick_player(server_id, slot_id, body.reason)
+    return _ok({"message": f"Player {slot_id} kicked"})
+
+
+@router.post("/{slot_id}/ban")
+def ban_player_from_list(
+    server_id: int,
+    slot_id: int,
+    body: BanFromPlayerRequest,
+    db: Annotated[Connection, Depends(get_db)],
+    admin: Annotated[dict, Depends(require_admin)],
+) -> dict:
+    ban = ServerService(db).ban_from_player(
+        server_id, slot_id, body.reason, body.duration_minutes,
+        banned_by=admin["username"],
+    )
+    return _ok(ban)