refactor(config): eliminate ErupeConfig global variable

Replace the mutable global `_config.ErupeConfig` with dependency
injection across 79 files. Config is now threaded through existing
paths: `ClientContext.RealClientMode` for packet encoding, `s.server.
erupeConfig` for channel handlers, and explicit parameters for utility
functions. This removes hidden coupling, enables test parallelism
without global save/restore, and prevents low-level packages from
reaching up to the config layer.

Key changes:
- Enrich ClientContext with RealClientMode for packet files
- Add mode parameter to CryptConn, mhfitem, mhfcourse functions
- Convert handlers_commands init() to lazy sync.Once initialization
- Delete global var, init(), and helper functions from config.go
- Update all tests to pass config explicitly

server/signserver/dbutils.go

@@ -105,7 +105,7 @@ func (s *Server) getUserRights(uid uint32) uint32 {
 	var rights uint32
 	if uid != 0 {
 		_ = s.db.QueryRow("SELECT rights FROM users WHERE id=$1", uid).Scan(&rights)
-		_, rights = mhfcourse.GetCourseStruct(rights)
+		_, rights = mhfcourse.GetCourseStruct(rights, s.erupeConfig.DefaultCourses)
 	}
 	return rights
 }

server/signserver/dbutils_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 	"time"
 
+	"erupe-ce/config"
 	"github.com/DATA-DOG/go-sqlmock"
 	"github.com/jmoiron/sqlx"
 	"go.uber.org/zap"
@@ -301,8 +302,9 @@ func newTestServerWithMock(t *testing.T) (*Server, sqlmock.Sqlmock) {
 	sqlxDB := sqlx.NewDb(db, "sqlmock")
 
 	server := &Server{
-		logger: zap.NewNop(),
-		db:     sqlxDB,
+		logger:      zap.NewNop(),
+		db:          sqlxDB,
+		erupeConfig: &_config.Config{},
 	}
 
 	return server, mock

server/signserver/session_test.go

@@ -75,7 +75,7 @@ func TestSessionStruct(t *testing.T) {
 		logger:    logger,
 		server:    nil,
 		rawConn:   conn,
-		cryptConn: network.NewCryptConn(conn),
+		cryptConn: network.NewCryptConn(conn, _config.ZZ),
 	}
 
 	if s.logger != logger {
@@ -145,7 +145,7 @@ func TestHandlePacketUnknownRequest(t *testing.T) {
 		logger:    logger,
 		server:    server,
 		rawConn:   conn,
-		cryptConn: network.NewCryptConn(conn),
+		cryptConn: network.NewCryptConn(conn, _config.ZZ),
 	}
 
 	bf := byteframe.NewByteFrame()
@@ -176,7 +176,7 @@ func TestHandlePacketWithDevModeLogging(t *testing.T) {
 		logger:    logger,
 		server:    server,
 		rawConn:   conn,
-		cryptConn: network.NewCryptConn(conn),
+		cryptConn: network.NewCryptConn(conn, _config.ZZ),
 	}
 
 	bf := byteframe.NewByteFrame()
@@ -214,7 +214,7 @@ func TestHandlePacketRequestTypes(t *testing.T) {
 				logger:    logger,
 				server:    server,
 				rawConn:   conn,
-				cryptConn: network.NewCryptConn(conn),
+				cryptConn: network.NewCryptConn(conn, _config.ZZ),
 			}
 
 			bf := byteframe.NewByteFrame()
@@ -324,7 +324,7 @@ func TestMockConnDeadlines(t *testing.T) {
 
 func TestSessionWithCryptConn(t *testing.T) {
 	conn := newMockConn()
-	cryptConn := network.NewCryptConn(conn)
+	cryptConn := network.NewCryptConn(conn, _config.ZZ)
 
 	if cryptConn == nil {
 		t.Fatal("NewCryptConn() returned nil")
@@ -361,7 +361,7 @@ func TestSessionWorkWithDevModeLogging(t *testing.T) {
 		logger:    logger,
 		server:    server,
 		rawConn:   serverConn,
-		cryptConn: network.NewCryptConn(serverConn),
+		cryptConn: network.NewCryptConn(serverConn, _config.ZZ),
 	}
 
 	_ = clientConn.Close()
@@ -386,7 +386,7 @@ func TestSessionWorkWithEmptyRead(t *testing.T) {
 		logger:    logger,
 		server:    server,
 		rawConn:   serverConn,
-		cryptConn: network.NewCryptConn(serverConn),
+		cryptConn: network.NewCryptConn(serverConn, _config.ZZ),
 	}
 
 	_ = clientConn.Close()

server/signserver/sign_server.go

@@ -101,7 +101,7 @@ func (s *Server) handleConnection(conn net.Conn) {
 		logger:    s.logger,
 		server:    s,
 		rawConn:   conn,
-		cryptConn: network.NewCryptConn(conn),
+		cryptConn: network.NewCryptConn(conn, s.erupeConfig.RealClientMode),
 	}
 
 	// Do the session's work.