feat(ui): add identity management for tenants and users

* Implement tenant and user creation in IdentityPage
* Add API calls for managing tenants and users
* Introduce tenant-scoped API requests
* Update sidebar to include identity navigation
* Create BooleanStatusBadge component for key status

internal/auth/keyring.go

@@ -1,14 +1,27 @@
 package auth
 
 import (
+	"crypto/rand"
+	"crypto/sha256"
 	"crypto/subtle"
+	"encoding/hex"
 	"fmt"
+	"strings"
+	"sync"
 
 	"git.warky.dev/wdevs/amcs/internal/config"
 )
 
 type Keyring struct {
-	keys []config.APIKey
+	mu             sync.RWMutex
+	keys           []config.APIKey
+	tenantsByKeyID map[string]string
+	managed        map[string]managedKey
+}
+
+type managedKey struct {
+	secretHash string
+	enabled    bool
 }
 
 func NewKeyring(keys []config.APIKey) (*Keyring, error) {
@@ -16,14 +29,112 @@ func NewKeyring(keys []config.APIKey) (*Keyring, error) {
 		return nil, fmt.Errorf("keyring requires at least one key")
 	}
 
-	return &Keyring{keys: append([]config.APIKey(nil), keys...)}, nil
+	tenantsByKeyID := make(map[string]string)
+	for _, key := range keys {
+		if tenantID := strings.TrimSpace(key.TenantID); tenantID != "" {
+			tenantsByKeyID[key.ID] = tenantID
+		}
+	}
+	return &Keyring{keys: append([]config.APIKey(nil), keys...), tenantsByKeyID: tenantsByKeyID, managed: make(map[string]managedKey)}, nil
+}
+
+// NewManagedKeyring is used when API credentials are administered in the
+// database rather than supplied through static configuration.
+func NewManagedKeyring() *Keyring {
+	return &Keyring{tenantsByKeyID: make(map[string]string), managed: make(map[string]managedKey)}
 }
 
 func (k *Keyring) Lookup(value string) (string, bool) {
+	k.mu.RLock()
+	defer k.mu.RUnlock()
 	for _, key := range k.keys {
 		if subtle.ConstantTimeCompare([]byte(key.Value), []byte(value)) == 1 {
 			return key.ID, true
 		}
 	}
+	hash := secretHash(value)
+	for keyID, key := range k.managed {
+		if key.enabled && subtle.ConstantTimeCompare([]byte(key.secretHash), []byte(hash)) == 1 {
+			return keyID, true
+		}
+	}
 	return "", false
 }
+
+// TenantForKey returns the tenant boundary assigned to keyID. Unassigned
+// configured keys retain the historical key-ID boundary for compatibility.
+func (k *Keyring) TenantForKey(keyID string) string {
+	k.mu.RLock()
+	defer k.mu.RUnlock()
+	if tenantID := k.tenantsByKeyID[keyID]; tenantID != "" {
+		return tenantID
+	}
+	return keyID
+}
+
+func (k *Keyring) AssignTenant(keyID, tenantID string) {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	if tenantID == "" {
+		delete(k.tenantsByKeyID, keyID)
+		return
+	}
+	k.tenantsByKeyID[keyID] = tenantID
+}
+
+func (k *Keyring) AddManaged(keyID, secretHash string, enabled bool) {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	k.managed[keyID] = managedKey{secretHash: secretHash, enabled: enabled}
+}
+
+func (k *Keyring) ConfiguredKeys() []config.APIKey {
+	k.mu.RLock()
+	defer k.mu.RUnlock()
+	return append([]config.APIKey(nil), k.keys...)
+}
+
+func (k *Keyring) IsConfigured(keyID string) bool {
+	k.mu.RLock()
+	defer k.mu.RUnlock()
+	for _, key := range k.keys {
+		if key.ID == keyID {
+			return true
+		}
+	}
+	return false
+}
+
+func (k *Keyring) IsSuperadmin(keyID string) bool {
+	k.mu.RLock()
+	defer k.mu.RUnlock()
+	for _, key := range k.keys {
+		if key.ID == keyID {
+			return key.Superadmin
+		}
+	}
+	return false
+}
+
+func (k *Keyring) SetManagedEnabled(keyID string, enabled bool) {
+	k.mu.Lock()
+	defer k.mu.Unlock()
+	if key, ok := k.managed[keyID]; ok {
+		key.enabled = enabled
+		k.managed[keyID] = key
+	}
+}
+
+func GenerateSecret() (string, string, error) {
+	b := make([]byte, 32)
+	if _, err := rand.Read(b); err != nil {
+		return "", "", err
+	}
+	secret := "amcs_" + hex.EncodeToString(b)
+	return secret, secretHash(secret), nil
+}
+
+func secretHash(secret string) string {
+	sum := sha256.Sum256([]byte(secret))
+	return hex.EncodeToString(sum[:])
+}