refactor(channelserver): extract Goocoo, Diva, Misc, Scenario, and Mercenary repositories

Move remaining raw s.server.db.* queries from handler files into
dedicated repository structs, completing the repository extraction
effort. Also adds SaveCharacterData and SaveHouseData to
CharacterRepository.

Fixes guild_hunts query to select both cats_used and start columns
to match the existing two-column Scan call. Adds slot index
validation in GoocooRepository to prevent SQL injection via
fmt.Sprintf.

server/channelserver/repo_misc.go

@@ -0,0 +1,29 @@
+package channelserver
+
+import (
+	"database/sql"
+
+	"github.com/jmoiron/sqlx"
+)
+
+// MiscRepository centralizes database access for miscellaneous game tables.
+type MiscRepository struct {
+	db *sqlx.DB
+}
+
+// NewMiscRepository creates a new MiscRepository.
+func NewMiscRepository(db *sqlx.DB) *MiscRepository {
+	return &MiscRepository{db: db}
+}
+
+// GetTrendWeapons returns the top 3 weapon IDs for a given weapon type, ordered by count descending.
+func (r *MiscRepository) GetTrendWeapons(weaponType uint8) (*sql.Rows, error) {
+	return r.db.Query("SELECT weapon_id FROM trend_weapons WHERE weapon_type=$1 ORDER BY count DESC LIMIT 3", weaponType)
+}
+
+// UpsertTrendWeapon increments the count for a weapon, inserting it if it doesn't exist.
+func (r *MiscRepository) UpsertTrendWeapon(weaponID uint16, weaponType uint8) error {
+	_, err := r.db.Exec(`INSERT INTO trend_weapons (weapon_id, weapon_type, count) VALUES ($1, $2, 1) ON CONFLICT (weapon_id) DO
+		UPDATE SET count = trend_weapons.count+1`, weaponID, weaponType)
+	return err
+}