feat: add SERVER_BINARY, SERVER_PARAMS, STEAMCMD_PATH env vars

- ProcessManager.Start() reads SERVER_BINARY and SERVER_PARAMS from env
  with platform-based defaults as fallback
- SteamCmdManager.run() reads STEAMCMD_PATH from env, defaults to
  'steamcmd'
- Makefile: add SERVER_BINARY/SERVER_PARAMS/STEAMCMD_PATH variables,
  copy stubs to dev-deploy in 'make dev', pass env vars to backend
- .gitignore: add bin/

.gitignore

@@ -2,6 +2,7 @@ node_modules/
 dist/
 frontend/dist/
 backend/embed/dist/
+bin/
 
 *.exe
 *.test

Makefile

@@ -7,6 +7,11 @@ CFG_DIR        ?= ../dev-deploy/serverfiles/cfg
 PROFILES_DIR   ?= ../dev-deploy/serverfiles/profiles
 DATA_DIR       ?= ../dev-deploy/data
 
+# Server/steamcmd overrides — set to use stubs in dev
+SERVER_BINARY  ?= arma3server_x64
+SERVER_PARAMS  ?= -server -world=empty -loadMissionToMemory -noPause
+STEAMCMD_PATH  ?= steamcmd
+
 backend:
 	cd backend && go build -o arma3-web-server ./cmd/server/
 
@@ -22,17 +27,19 @@ copyfrontend:
 build: frontend copyfrontend backend
 
 run:
-	cd backend && SERVERFILE_DIR=$(SERVERFILE_DIR) MODS_DIR=$(MODS_DIR) CFG_DIR=$(CFG_DIR) PROFILES_DIR=$(PROFILES_DIR) DATA_DIR=$(DATA_DIR) GIN_MODE=debug go run ./cmd/server/
+	cd backend && SERVERFILE_DIR=$(SERVERFILE_DIR) MODS_DIR=$(MODS_DIR) CFG_DIR=$(CFG_DIR) PROFILES_DIR=$(PROFILES_DIR) DATA_DIR=$(DATA_DIR) SERVER_BINARY=$(SERVER_BINARY) SERVER_PARAMS="$(SERVER_PARAMS)" STEAMCMD_PATH=$(STEAMCMD_PATH) GIN_MODE=debug go run ./cmd/server/
 
 dev:
-	mkdir -p backend/embed/dist
+	mkdir -p backend/embed/dist bin
 	test -f backend/embed/dist/dev.txt || touch backend/embed/dist/dev.txt
-	cd backend && SERVERFILE_DIR=$(SERVERFILE_DIR) MODS_DIR=$(MODS_DIR) CFG_DIR=$(CFG_DIR) PROFILES_DIR=$(PROFILES_DIR) DATA_DIR=$(DATA_DIR) GIN_MODE=debug go run ./cmd/server/ &
+	cp backend/internal/services/testdata/arma3server_x64 $(SERVERFILE_DIR)/
+	cp backend/internal/services/testdata/steamcmd bin/
+	cd backend && PATH=$(CURDIR)/bin:$$PATH SERVERFILE_DIR=$(SERVERFILE_DIR) MODS_DIR=$(MODS_DIR) CFG_DIR=$(CFG_DIR) PROFILES_DIR=$(PROFILES_DIR) DATA_DIR=$(DATA_DIR) SERVER_BINARY=$(SERVER_BINARY) SERVER_PARAMS="$(SERVER_PARAMS)" STEAMCMD_PATH=$(CURDIR)/bin/steamcmd GIN_MODE=debug go run ./cmd/server/ &
 	cd frontend && npm run dev
 
 clean:
 	rm -f backend/arma3-web-server
-	rm -rf frontend/dist backend/embed/dist
+	rm -rf frontend/dist backend/embed/dist bin
 
 test-backend:
 	cd backend && go test ./...

backend/internal/services/server_process.go

@@ -85,10 +85,17 @@ func (pm *ProcessManager) Start() error {
 		return fmt.Errorf("save was_running: %w", err)
 	}
 
-	binName := "arma3server_x64"
+	if env := os.Getenv("SERVER_PARAMS"); env != "" {
+		s.ServerParameters = env
+	}
+
+	binName := os.Getenv("SERVER_BINARY")
+	if binName == "" {
+		binName = "arma3server_x64"
 		if s.Platform == "windows" {
 			binName = "arma3server_x64.exe"
 		}
+	}
 	binPath := filepath.Join(pm.serverfileDir, binName)
 
 	ctx, cancel := context.WithCancel(context.Background())

backend/internal/services/steamcmd.go

@@ -90,7 +90,11 @@ func (s *SteamCmdManager) run(label string, args []string) error {
 
 	s.streamer.Broadcast("steamcmd", "[STEAMCMD] "+label+" starting...")
 
-	cmd := exec.CommandContext(ctx, "steamcmd", args...)
+	steamcmdPath := os.Getenv("STEAMCMD_PATH")
+	if steamcmdPath == "" {
+		steamcmdPath = "steamcmd"
+	}
+	cmd := exec.CommandContext(ctx, steamcmdPath, args...)
 
 	stdout, err := cmd.StdoutPipe()
 	if err != nil {