Complete DIDView.vue triple migration and refactor template handlers

- Fix DIDView.vue notification migration: add missing NOTIFY_SERVER_ACCESS_ERROR and NOTIFY_NO_IDENTITY_ERROR imports
- Refactor 5 inline template handlers to proper class methods (goBack, toggleDidDetails, showLargeProfileImage, showLargeIdenticon, hideLargeImage)
- Update notification validation script to exclude createNotifyHelpers initialization patterns
- DIDView.vue now fully compliant: database migration + SQL abstraction + notification migration complete

Improves code organization, testability, and follows Vue.js best practices for template/class separation. All linting passes without errors.

src/utils/PlatformServiceMixin.ts

@@ -913,6 +913,47 @@ export const PlatformServiceMixin = {
       }));
     },
 
+    /**
+     * Get single contact by DID - $getContact()
+     * Eliminates verbose single contact query patterns
+     * @param did Contact DID to retrieve
+     * @returns Promise<Contact | null> Contact object or null if not found
+     */
+    async $getContact(did: string): Promise<Contact | null> {
+      const results = await this.$dbQuery(
+        "SELECT * FROM contacts WHERE did = ?",
+        [did],
+      );
+
+      if (!results || !results.values || results.values.length === 0) {
+        return null;
+      }
+
+      const contactData = this._mapColumnsToValues(
+        results.columns,
+        results.values,
+      );
+      return contactData.length > 0 ? (contactData[0] as Contact) : null;
+    },
+
+    /**
+     * Delete contact by DID - $deleteContact()
+     * Eliminates verbose contact deletion patterns
+     * @param did Contact DID to delete
+     * @returns Promise<boolean> Success status
+     */
+    async $deleteContact(did: string): Promise<boolean> {
+      try {
+        await this.$dbExec("DELETE FROM contacts WHERE did = ?", [did]);
+        // Invalidate contacts cache
+        this._invalidateCache("contacts_all");
+        return true;
+      } catch (error) {
+        logger.error("[PlatformServiceMixin] Error deleting contact:", error);
+        return false;
+      }
+    },
+
     /**
      * Generic entity insertion - $insertEntity()
      * Eliminates verbose INSERT patterns for any entity
@@ -1197,6 +1238,8 @@ export interface IPlatformServiceMixin {
   $insertContact(contact: Partial<Contact>): Promise<boolean>;
   $updateContact(did: string, changes: Partial<Contact>): Promise<boolean>;
   $getAllContacts(): Promise<Contact[]>;
+  $getContact(did: string): Promise<Contact | null>;
+  $deleteContact(did: string): Promise<boolean>;
   $contactCount(): Promise<number>;
   $insertEntity(
     tableName: string,
@@ -1316,6 +1359,8 @@ declare module "@vue/runtime-core" {
     $insertContact(contact: Partial<Contact>): Promise<boolean>;
     $updateContact(did: string, changes: Partial<Contact>): Promise<boolean>;
     $getAllContacts(): Promise<Contact[]>;
+    $getContact(did: string): Promise<Contact | null>;
+    $deleteContact(did: string): Promise<boolean>;
     $insertEntity(
       tableName: string,
       entity: Record<string, unknown>,