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

network/mhfpacket/msg_mhf_update_myhouse_info.go

@@ -23,11 +23,11 @@ func (m *MsgMhfUpdateMyhouseInfo) Opcode() network.PacketID {
 // Parse parses the packet from binary
 func (m *MsgMhfUpdateMyhouseInfo) Parse(bf *byteframe.ByteFrame, ctx *clientctx.ClientContext) error {
 	m.AckHandle = bf.ReadUint32()
-	if _config.ErupeConfig.RealClientMode >= _config.G10 {
+	if ctx.RealClientMode >= _config.G10 {
 		m.Data = bf.ReadBytes(362)
-	} else if _config.ErupeConfig.RealClientMode >= _config.GG {
+	} else if ctx.RealClientMode >= _config.GG {
 		m.Data = bf.ReadBytes(338)
-	} else if _config.ErupeConfig.RealClientMode >= _config.F5 {
+	} else if ctx.RealClientMode >= _config.F5 {
 		// G1 is a guess
 		m.Data = bf.ReadBytes(314)
 	} else {