Align email-api and page-fetcher-api namespaces to Api.* convention

Fixes inconsistency where email-api used EmailApi.* and page-fetcher-api
used PageFetcherApi.*, while cv-matcher-api and rag-api use the generic
Api.* namespace. All four API projects now follow the same pattern.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Apis/email-api/Controllers/EmailController.cs

@@ -1,9 +1,9 @@
+using Api.Services;
 using EmailApi.Models.Requests;
-using EmailApi.Services;
 using Microsoft.AspNetCore.Mvc;
 using Swashbuckle.AspNetCore.Annotations;
 
-namespace EmailApi.Controllers;
+namespace Api.Controllers;
 
 /// <summary>
 /// Internal email relay. Accepts an HTML body fragment from trusted callers