docs: add doc.go files and godoc comments to all packages

Add package-level documentation (doc.go) to all 22 first-party
packages and godoc comments to ~150 previously undocumented
exported symbols across common/, network/, and server/.

network/mhfpacket/doc.go

@@ -0,0 +1,4 @@
+// Package mhfpacket defines the struct representations and binary
+// serialization for every MHF network packet (~400 message types). Each
+// packet implements the [MHFPacket] interface (Parse, Build, Opcode).
+package mhfpacket

network/mhfpacket/msg_mhf_enumerate_guild.go

@@ -7,6 +7,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// EnumerateGuildType specifies the search/sort criteria for guild enumeration.
 type EnumerateGuildType uint8
 
 const (

network/mhfpacket/msg_mhf_operate_guild.go

@@ -8,6 +8,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// OperateGuildAction identifies the guild management action to perform.
 type OperateGuildAction uint8
 
 const (

network/mhfpacket/msg_mhf_operate_guild_member.go

@@ -8,6 +8,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// OperateGuildMemberAction identifies the guild member management action.
 type OperateGuildMemberAction uint8
 
 const (

network/mhfpacket/msg_mhf_operate_joint.go

@@ -8,6 +8,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// OperateJointAction identifies the alliance (joint) operation to perform.
 type OperateJointAction uint8
 
 const (

network/mhfpacket/msg_mhf_oprt_mail.go

@@ -8,6 +8,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// OperateMailOperation identifies the mail operation to perform.
 type OperateMailOperation uint8
 
 const (

network/mhfpacket/msg_mhf_set_ca_achievement_hist.go

@@ -8,6 +8,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// CaAchievementHist is a single entry in the CA achievement history packet.
 type CaAchievementHist struct {
 	Unk0 uint32
 	Unk1 uint8

network/mhfpacket/msg_mhf_update_guacot.go

@@ -7,6 +7,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// Goocoo represents a single Goocoo (guacot) companion entry in an update packet.
 type Goocoo struct {
 	Index uint32
 	Data1 []int16

network/mhfpacket/msg_mhf_update_guild_icon.go

@@ -8,6 +8,7 @@ import (
 	"erupe-ce/network/clientctx"
 )
 
+// GuildIconMsgPart represents one graphical part of a guild icon (emblem).
 type GuildIconMsgPart struct {
 	Index    uint16
 	ID       uint16