feat(credstore): add Store.ListProfiles for profile enumeration

credstore/bundle.go

@@ -84,6 +84,42 @@ func (s *Store) ListBundle(profile string) ([]string, error) {
 	return s.bundleBareKeys(profile)
 }
 
+// ListProfiles returns the sorted distinct profiles that have at least one
+// stored key under this service. Like ListBundle it is not allowlist-gated —
+// it reports stored reality (§1.5.2 gates writes/deletes, not reads). A
+// service with no stored items returns (nil, nil). It exists so a CLI can
+// offer a "profiles list" affordance without shelling out to OS keyring
+// tools: the profile segment is not secret (§1.12), and discovering which
+// profiles exist must not require dumping the keychain by hand. An item key
+// with no '/' separator (never written by this package) is ignored rather
+// than surfaced as a phantom profile.
+func (s *Store) ListProfiles() ([]string, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	if s.closed {
+		return nil, ErrStoreClosed
+	}
+	all, err := s.be.listKeys()
+	if err != nil {
+		return nil, err
+	}
+	seen := map[string]struct{}{}
+	var profiles []string
+	for _, ik := range all {
+		profile, _, found := strings.Cut(ik, "/")
+		if !found || profile == "" {
+			continue
+		}
+		if _, dup := seen[profile]; dup {
+			continue
+		}
+		seen[profile] = struct{}{}
+		profiles = append(profiles, profile)
+	}
+	sort.Strings(profiles)
+	return profiles, nil
+}
+
 // DeleteBundle removes every key under profile (config clear, §1.7). It
 // is idempotent (a valid profile with no keys → (nil, nil)) and not
 // allowlist-gated. It does not fail-fast: every key is attempted; if any

credstore/bundle_test.go

@@ -61,6 +61,42 @@ func TestListBundleClosed(t *testing.T) {
 	}
 }
 
+func TestListProfiles(t *testing.T) {
+	s := openMem(t)
+	if got, err := s.ListProfiles(); err != nil || got != nil {
+		t.Fatalf("ListProfiles(empty store) = (%v,%v), want (nil,nil)", got, err)
+	}
+
+	mustSet(t, s, "work", "oauth_token", "1")
+	mustSet(t, s, "default", "oauth_token", "2")
+	mustSet(t, s, "default", "second_key", "3") // dedupe: two keys, one profile
+	got, err := s.ListProfiles()
+	if err != nil {
+		t.Fatalf("ListProfiles: %v", err)
+	}
+	eqStrings(t, "ListProfiles", got, []string{"default", "work"})
+
+	// Not allowlist-gated: a profile whose only key was stored directly
+	// (legacy / another tool run) is still reported — stored reality.
+	if err := memOf(t, s).set("legacy/legacy_key", "x", false); err != nil {
+		t.Fatalf("seed legacy profile: %v", err)
+	}
+	// A malformed item key with no separator is ignored, not a profile.
+	if err := memOf(t, s).set("noslash", "x", false); err != nil {
+		t.Fatalf("seed malformed key: %v", err)
+	}
+	got, _ = s.ListProfiles()
+	eqStrings(t, "ListProfiles after legacy", got, []string{"default", "legacy", "work"})
+}
+
+func TestListProfilesClosed(t *testing.T) {
+	s, _ := Open("svc", &Options{Backend: BackendMemory})
+	_ = s.Close()
+	if _, err := s.ListProfiles(); !errors.Is(err, ErrStoreClosed) {
+		t.Fatalf("ListProfiles after Close = %v, want ErrStoreClosed", err)
+	}
+}
+
 func TestDeleteBundle(t *testing.T) {
 	s := openMem(t)
 	if _, err := s.DeleteBundle(""); !errors.Is(err, ErrRefEmpty) {