UX S1: sell-all guard against magic-item deletion (B1)

`!adventure sell all` and `!adventure sell <name>` previously treated
Type=="magic_item" rows as bulk loot, silently deleting bonded curios for
their base coin Value. Mirror the existing MasterworkGear/Arena/card
branch and reroute the player to `!adventure equip-magic`.

Tally kept curios in the sell-all summary; surface a dedicated
empty-rejection message when the only contents are curios; add the same
guard to the single-item path.

Tests cover: mixed bag (magic item preserved, junk sells), curio-only
bag (no-op + reroute), explicit sell <curio name> (refused + reroute).

internal/plugin/adventure_shop.go

@@ -841,11 +841,19 @@ func (p *AdventurePlugin) advSellAll(userID id.UserID) string {
 	var sold int
 	var keptSpecial int
 	var keptConsumable int
+	var keptMagic int
 	for _, item := range items {
 		if item.Type == "MasterworkGear" || item.Type == "ArenaGear" || item.Type == "card" {
 			keptSpecial++
 			continue
 		}
+		if item.Type == "magic_item" {
+			// B1: magic items are bonded curios, not bulk loot — sell-all must
+			// never silently delete them. Route the player to !adventure
+			// equip-magic instead.
+			keptMagic++
+			continue
+		}
 		if item.Type == "consumable" {
 			keptConsumable++
 			continue
@@ -859,6 +867,10 @@ func (p *AdventurePlugin) advSellAll(userID id.UserID) string {
 
 	if sold == 0 {
 		switch {
+		case keptMagic > 0 && (keptSpecial > 0 || keptConsumable > 0):
+			return "Your inventory only contains special gear, curios, and/or consumables. The merchant won't touch any of it. Use `!adventure equip-magic` for curios, `!adventure equip` for gear, or `!adventure sell <name>` for individual consumables."
+		case keptMagic > 0:
+			return "Your inventory only contains curios (magic items). The merchant doesn't deal in those. Use `!adventure equip-magic` instead."
 		case keptSpecial > 0 && keptConsumable > 0:
 			return "Your inventory only contains special gear and consumables. The merchant won't touch any of it. Use `!adventure equip` for gear or `!adventure sell <name>` for individual consumables."
 		case keptSpecial > 0:
@@ -886,6 +898,9 @@ func (p *AdventurePlugin) advSellAll(userID id.UserID) string {
 	if keptConsumable > 0 {
 		msg += fmt.Sprintf("\n(%d consumable(s) kept — `sell all` doesn't touch them. Sell explicitly with `!adventure sell <name>`.)", keptConsumable)
 	}
+	if keptMagic > 0 {
+		msg += fmt.Sprintf("\n(%d curio(s) kept — `!adventure equip-magic` to bond them. The merchant wouldn't know what to do with them.)", keptMagic)
+	}
 	return msg
 }
 
@@ -901,6 +916,9 @@ func (p *AdventurePlugin) advSellItem(userID id.UserID, itemName string) string
 			if item.Type == "MasterworkGear" || item.Type == "ArenaGear" || item.Type == "card" {
 				return fmt.Sprintf("**%s** is special gear. The merchant won't touch it. Use `!adventure equip` to equip it.", item.Name)
 			}
+			if item.Type == "magic_item" {
+				return fmt.Sprintf("**%s** is a curio — the merchant doesn't deal in those. Use `!adventure equip-magic` to bond it instead.", item.Name)
+			}
 			if err := removeAdvInventoryItem(item.ID); err != nil {
 				return "Failed to sell that item."
 			}

internal/plugin/adventure_shop_sell_test.go

@@ -0,0 +1,119 @@
+package plugin
+
+import (
+	"strings"
+	"testing"
+
+	"gogobee/internal/db"
+	"maunium.net/go/mautrix/id"
+)
+
+// freshShopTestDB spins up an empty DB in a tempdir for the sell-path tests.
+// Distinct from setupAuditTestDB, which clones the prod snapshot.
+func freshShopTestDB(t *testing.T) {
+	t.Helper()
+	dir := t.TempDir()
+	db.Close()
+	if err := db.Init(dir); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(db.Close)
+}
+
+// TestSellAll_PreservesMagicItems — B1 (data-loss blocker): `sell all` must
+// route around curios (Type=="magic_item") so a careless liquidation can't
+// silently delete a Legendary Ring. Junk in the same bag still sells.
+func TestSellAll_PreservesMagicItems(t *testing.T) {
+	freshShopTestDB(t)
+	uid := id.UserID("@sellall_magic:test")
+
+	curio := AdvItem{Name: "Ring of Protection", Type: "magic_item", Tier: 3, Value: 500}
+	junk := AdvItem{Name: "Iron Ore", Type: "material", Tier: 1, Value: 40}
+	if err := addAdvInventoryItem(uid, curio); err != nil {
+		t.Fatal(err)
+	}
+	if err := addAdvInventoryItem(uid, junk); err != nil {
+		t.Fatal(err)
+	}
+
+	euro := &EuroPlugin{}
+	euro.ensureBalance(uid)
+	p := &AdventurePlugin{euro: euro}
+
+	msg := p.advSellAll(uid)
+	if !strings.Contains(msg, "Sold 1 item") {
+		t.Errorf("expected exactly one item sold, msg=%q", msg)
+	}
+	if !strings.Contains(strings.ToLower(msg), "curio") {
+		t.Errorf("sell-all summary should call out kept curios, msg=%q", msg)
+	}
+
+	left, err := loadAdvInventory(uid)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(left) != 1 || left[0].Type != "magic_item" {
+		t.Fatalf("magic item not preserved: %+v", left)
+	}
+
+	// Payout reflects only the junk's €40 (5% pot cut → ~€38 credited).
+	bal := euro.GetBalance(uid)
+	if bal <= 0 || bal > 40 {
+		t.Errorf("payout %v outside expected (0,40] for €40 junk", bal)
+	}
+}
+
+// TestSellAll_OnlyMagicItems — when the bag is curios only, sell-all reroutes
+// to !adventure equip-magic and touches nothing.
+func TestSellAll_OnlyMagicItems(t *testing.T) {
+	freshShopTestDB(t)
+	uid := id.UserID("@sellall_only_magic:test")
+
+	if err := addAdvInventoryItem(uid, AdvItem{Name: "Cloak of Elvenkind", Type: "magic_item", Value: 300}); err != nil {
+		t.Fatal(err)
+	}
+
+	euro := &EuroPlugin{}
+	euro.ensureBalance(uid)
+	p := &AdventurePlugin{euro: euro}
+
+	msg := p.advSellAll(uid)
+	if !strings.Contains(msg, "equip-magic") {
+		t.Errorf("expected reroute to equip-magic, msg=%q", msg)
+	}
+	if euro.GetBalance(uid) != 0 {
+		t.Errorf("balance moved on curio-only sell-all: %v", euro.GetBalance(uid))
+	}
+	left, _ := loadAdvInventory(uid)
+	if len(left) != 1 {
+		t.Errorf("curio deleted by sell-all: %+v", left)
+	}
+}
+
+// TestSellItem_MagicItemRerouted — explicit `sell <curio name>` must refuse
+// and point the player at the bonding command.
+func TestSellItem_MagicItemRerouted(t *testing.T) {
+	freshShopTestDB(t)
+	uid := id.UserID("@sellone_magic:test")
+
+	curio := AdvItem{Name: "Amulet of Health", Type: "magic_item", Value: 750}
+	if err := addAdvInventoryItem(uid, curio); err != nil {
+		t.Fatal(err)
+	}
+
+	euro := &EuroPlugin{}
+	euro.ensureBalance(uid)
+	p := &AdventurePlugin{euro: euro}
+
+	msg := p.advSellItem(uid, "amulet")
+	if !strings.Contains(msg, "equip-magic") {
+		t.Errorf("expected reroute to equip-magic, msg=%q", msg)
+	}
+	if euro.GetBalance(uid) != 0 {
+		t.Errorf("balance moved on refused curio sale: %v", euro.GetBalance(uid))
+	}
+	left, _ := loadAdvInventory(uid)
+	if len(left) != 1 {
+		t.Errorf("curio deleted by refused sale: %+v", left)
+	}
+}