refactor: improve type safety in endorser server and common interfaces

- Add proper type definitions for AxiosErrorResponse with detailed error structure
- Make KeyMeta fields required where needed (publicKeyHex, mnemonic, derivationPath)
- Add QuantitativeValue type for consistent handling of numeric values
- Fix type assertions and compatibility between GenericVerifiableCredential and its extensions
- Improve error handling with proper type guards and assertions
- Update VerifiableCredentialClaim interface with required fields
- Add proper type assertions for claim objects in claimSummary and claimSpecialDescription
- Fix BLANK_GENERIC_SERVER_RECORD to include required @context field

Note: Some type issues with KeyMeta properties remain to be investigated,
as TypeScript is not recognizing the updated interface changes.

src/interfaces/common.ts

@@ -1,6 +1,6 @@
 // similar to VerifiableCredentialSubject... maybe rename this
 export interface GenericVerifiableCredential {
-  "@context"?: string;
+  "@context": string | string[];
   "@type": string;
   [key: string]: unknown;
 }
@@ -34,3 +34,144 @@ export interface ErrorResult extends ResultWithType {
   type: "error";
   error: InternalError;
 }
+
+export interface KeyMeta {
+  did: string;
+  name?: string;
+  publicKeyHex: string;
+  mnemonic: string;
+  derivationPath: string;
+  registered?: boolean;
+  profileImageUrl?: string;
+  [key: string]: unknown;
+}
+
+export interface QuantitativeValue extends GenericVerifiableCredential {
+  '@type': 'QuantitativeValue';
+  '@context': string | string[];
+  amountOfThisGood: number;
+  unitCode: string;
+  [key: string]: unknown;
+}
+
+export interface AxiosErrorResponse {
+  message?: string;
+  response?: {
+    data?: {
+      error?: {
+        message?: string;
+      };
+      [key: string]: unknown;
+    };
+    status?: number;
+    config?: unknown;
+  };
+  config?: unknown;
+  [key: string]: unknown;
+}
+
+export interface UserInfo {
+  did: string;
+  name: string;
+  publicEncKey: string;
+  registered: boolean;
+  profileImageUrl?: string;
+  nextPublicEncKeyHash?: string;
+}
+
+export interface CreateAndSubmitClaimResult {
+  success: boolean;
+  error?: string;
+  handleId?: string;
+}
+
+export interface PlanSummaryRecord {
+  handleId: string;
+  issuer: string;
+  claim: GenericVerifiableCredential;
+  [key: string]: unknown;
+}
+
+export interface Agent {
+  identifier?: string;
+  did?: string;
+  [key: string]: unknown;
+}
+
+export interface ClaimObject {
+  '@type': string;
+  '@context'?: string | string[];
+  fulfills?: Array<{
+    '@type': string;
+    identifier?: string;
+    [key: string]: unknown;
+  }>;
+  object?: GenericVerifiableCredential;
+  agent?: Agent;
+  participant?: {
+    identifier?: string;
+    [key: string]: unknown;
+  };
+  identifier?: string;
+  [key: string]: unknown;
+}
+
+export interface VerifiableCredentialClaim {
+  '@context': string | string[];
+  '@type': string;
+  type: string[];
+  credentialSubject: ClaimObject;
+  [key: string]: unknown;
+}
+
+export interface GiveVerifiableCredential extends GenericVerifiableCredential {
+  '@type': 'GiveAction';
+  '@context': string | string[];
+  object?: GenericVerifiableCredential;
+  agent?: Agent;
+  participant?: {
+    identifier?: string;
+    [key: string]: unknown;
+  };
+  fulfills?: Array<{
+    '@type': string;
+    identifier?: string;
+    [key: string]: unknown;
+  }>;
+  [key: string]: unknown;
+}
+
+export interface OfferVerifiableCredential extends GenericVerifiableCredential {
+  '@type': 'OfferAction';
+  '@context': string | string[];
+  object?: GenericVerifiableCredential;
+  agent?: Agent;
+  participant?: {
+    identifier?: string;
+    [key: string]: unknown;
+  };
+  itemOffered?: {
+    description?: string;
+    isPartOf?: {
+      '@type': string;
+      identifier: string;
+      [key: string]: unknown;
+    };
+    [key: string]: unknown;
+  };
+  [key: string]: unknown;
+}
+
+export interface RegisterVerifiableCredential extends GenericVerifiableCredential {
+  '@type': 'RegisterAction';
+  '@context': string | string[];
+  agent: {
+    identifier: string;
+  };
+  object: string;
+  participant?: {
+    identifier: string;
+  };
+  identifier?: string;
+  [key: string]: unknown;
+}