N4/E1: T4 Estate vault — 10-slot protected item storage

The Tier-4 "Established" home now unlocks a vault: `!adventure vault
[store|take] <item>` moves items in and out of a 10-slot pool that shelters
them from `!sell all`, crafting, and combat consumption. It is also E2
gifting's prerequisite plumbing.

Implemented as a single `in_vault` flag on adventure_inventory rather than a
parallel table: a stowed item keeps its identity (id, temper, everything) and
loadAdvInventory filters it out, so a vaulted item drops out of every play
surface with one flag change and comes back untouched. DEFAULT 0 = "in play",
correct for every pre-existing row, so no bootstrap backfill.

Golden byte-identical; go test ./... green.

Claude-Session: https://claude.ai/code/session_017mEwUmmS7aQTP2NQXj6rUa

internal/plugin/adventure_vault_test.go

@@ -0,0 +1,138 @@
+package plugin
+
+import (
+	"strings"
+	"testing"
+
+	"gogobee/internal/db"
+
+	"maunium.net/go/mautrix/id"
+)
+
+func vaultTestDB(t *testing.T) {
+	t.Helper()
+	dir := t.TempDir()
+	db.Close()
+	if err := db.Init(dir); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(db.Close)
+}
+
+func seedVaultItem(t *testing.T, user id.UserID, name string, value int64) {
+	t.Helper()
+	if err := addAdvInventoryItem(user, AdvItem{Name: name, Type: "treasure", Tier: 3, Value: value}); err != nil {
+		t.Fatal(err)
+	}
+}
+
+// TestVaultStoreTakeRoundTrip: an item vaulted leaves the active inventory and
+// joins the vault; taken back, it reverses exactly.
+func TestVaultStoreTakeRoundTrip(t *testing.T) {
+	vaultTestDB(t)
+	user := id.UserID("@vault:test.invalid")
+	seedVaultItem(t, user, "Jeweled Crown", 5000)
+
+	if got := vaultStoreItem(user, "crown"); !strings.Contains(got, "Stowed") {
+		t.Fatalf("store reply = %q, want a stow confirmation", got)
+	}
+
+	inv, _ := loadAdvInventory(user)
+	if len(inv) != 0 {
+		t.Fatalf("active inventory = %d items, want 0 (item is vaulted)", len(inv))
+	}
+	vault, _ := loadAdvVault(user)
+	if len(vault) != 1 || vault[0].Name != "Jeweled Crown" {
+		t.Fatalf("vault = %+v, want the crown", vault)
+	}
+
+	if got := vaultTakeItem(user, "crown"); !strings.Contains(got, "back into your pack") {
+		t.Fatalf("take reply = %q, want a retrieval confirmation", got)
+	}
+	inv, _ = loadAdvInventory(user)
+	if len(inv) != 1 {
+		t.Fatalf("active inventory = %d items, want 1 after take", len(inv))
+	}
+	if n := advVaultCount(user); n != 0 {
+		t.Fatalf("vault count = %d, want 0", n)
+	}
+}
+
+// TestVaultCapacity: the 10th item stores, the 11th is refused, and the refusal
+// leaves the item in the active inventory.
+func TestVaultCapacity(t *testing.T) {
+	vaultTestDB(t)
+	user := id.UserID("@vaultcap:test.invalid")
+	for i := 0; i < vaultCapacity; i++ {
+		seedVaultItem(t, user, "Gem", 100)
+		if got := vaultStoreItem(user, "Gem"); !strings.Contains(got, "Stowed") {
+			t.Fatalf("store %d reply = %q, want success", i, got)
+		}
+	}
+	if n := advVaultCount(user); n != vaultCapacity {
+		t.Fatalf("vault count = %d, want %d", n, vaultCapacity)
+	}
+
+	seedVaultItem(t, user, "Overflow Gem", 100)
+	got := vaultStoreItem(user, "Overflow Gem")
+	if !strings.Contains(got, "full") {
+		t.Fatalf("11th store reply = %q, want a full-vault refusal", got)
+	}
+	// The refused item is still in play.
+	inv, _ := loadAdvInventory(user)
+	if len(inv) != 1 || inv[0].Name != "Overflow Gem" {
+		t.Fatalf("active inventory = %+v, want the overflow gem left in play", inv)
+	}
+}
+
+// TestVaultShieldsFromSellAll: `!sell all` liquidates loadAdvInventory, which a
+// vaulted item is no longer part of — the whole point of the vault.
+func TestVaultShieldsFromSellAll(t *testing.T) {
+	vaultTestDB(t)
+	user := id.UserID("@vaultsell:test.invalid")
+	seedVaultItem(t, user, "Heirloom", 9000)
+	seedVaultItem(t, user, "Junk", 5)
+
+	if got := vaultStoreItem(user, "Heirloom"); !strings.Contains(got, "Stowed") {
+		t.Fatalf("store reply = %q", got)
+	}
+	// What sell-all would consume:
+	sellable, _ := loadAdvInventory(user)
+	if len(sellable) != 1 || sellable[0].Name != "Junk" {
+		t.Fatalf("sellable inventory = %+v, want only Junk (heirloom sheltered)", sellable)
+	}
+}
+
+// TestVaultGate: below Tier 4 the vault is locked; at Tier 4 it opens.
+func TestVaultGate(t *testing.T) {
+	locked := &AdventureCharacter{HouseTier: 3}
+	if ok, msg := vaultUnlocked(locked); ok || msg == "" {
+		t.Fatalf("tier 3: ok=%v msg=%q, want locked with a refusal", ok, msg)
+	}
+	open := &AdventureCharacter{HouseTier: 4}
+	if ok, msg := vaultUnlocked(open); !ok || msg != "" {
+		t.Fatalf("tier 4: ok=%v msg=%q, want unlocked", ok, msg)
+	}
+}
+
+// TestSetItemVaultedIsOwnerScoped: another user's id cannot be flipped.
+func TestSetItemVaultedIsOwnerScoped(t *testing.T) {
+	vaultTestDB(t)
+	owner := id.UserID("@owner:test.invalid")
+	intruder := id.UserID("@intruder:test.invalid")
+	seedVaultItem(t, owner, "Relic", 1000)
+	items, _ := loadAdvInventory(owner)
+	if len(items) != 1 {
+		t.Fatalf("setup: owner inventory = %d, want 1", len(items))
+	}
+	moved, err := setItemVaulted(intruder, items[0].ID, true)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if moved {
+		t.Fatalf("intruder moved the owner's item; want no-op")
+	}
+	if advVaultCount(owner) != 0 {
+		t.Fatalf("owner's item was vaulted by an intruder")
+	}
+}