Phases 3 & 4: Complete data access architecture migration

Phase 3 — eliminated ApplicationDbContext from all non-exempt controllers,
routing all data access through IUnitOfWork. Added IPlainRepository<T> for
the four platform entities (Announcement, BannedIp, DashboardTip, ReleaseNote)
that intentionally don't extend BaseEntity and therefore can't use the
constrained IRepository<T>. Added permanent-exception comments to the 18
controllers that legitimately retain direct DbContext access (Identity infra,
cross-tenant platform ops, bulk streaming exports).

Phase 4 — added EnforceDataAccessArchitecture() to Program.cs, a startup
gate that reflects over every Controller subclass and throws at boot if any
non-exempt controller injects ApplicationDbContext. The app cannot start with
a violation.

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

src/PowderCoating.Web/Controllers/UnsubscribeController.cs

@@ -1,8 +1,7 @@
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.AspNetCore.RateLimiting;
-using Microsoft.EntityFrameworkCore;
-using PowderCoating.Infrastructure.Data;
+using PowderCoating.Core.Interfaces;
 using PowderCoating.Shared.Constants;
 
 namespace PowderCoating.Web.Controllers;
@@ -15,12 +14,12 @@ namespace PowderCoating.Web.Controllers;
 [EnableRateLimiting(AppConstants.RateLimitPolicies.Public)]
 public class UnsubscribeController : Controller
 {
-    private readonly ApplicationDbContext _context;
+    private readonly IUnitOfWork _unitOfWork;
     private readonly ILogger<UnsubscribeController> _logger;
 
-    public UnsubscribeController(ApplicationDbContext context, ILogger<UnsubscribeController> logger)
+    public UnsubscribeController(IUnitOfWork unitOfWork, ILogger<UnsubscribeController> logger)
     {
-        _context = context;
+        _unitOfWork = unitOfWork;
         _logger = logger;
     }
 
@@ -38,11 +37,10 @@ public class UnsubscribeController : Controller
 
         try
         {
-            // Bypass global query filters so we can find the customer by token
+            // ignoreQueryFilters=true so we can find the customer by token
             // regardless of company context (the user clicking is not authenticated)
-            var customer = await _context.Customers
-                .IgnoreQueryFilters()
-                .FirstOrDefaultAsync(c => c.UnsubscribeToken == token && !c.IsDeleted);
+            var customer = await _unitOfWork.Customers.FirstOrDefaultAsync(
+                c => c.UnsubscribeToken == token && !c.IsDeleted, ignoreQueryFilters: true);
 
             if (customer == null)
             {
@@ -52,7 +50,6 @@ public class UnsubscribeController : Controller
 
             if (!customer.NotifyByEmail)
             {
-                // Already unsubscribed — show success page anyway (idempotent)
                 ViewBag.CustomerName = customer.CompanyName ?? $"{customer.ContactFirstName} {customer.ContactLastName}".Trim();
                 ViewBag.AlreadyUnsubscribed = true;
                 return View("EmailConfirm");
@@ -60,7 +57,7 @@ public class UnsubscribeController : Controller
 
             customer.NotifyByEmail = false;
             customer.UpdatedAt = DateTime.UtcNow;
-            await _context.SaveChangesAsync();
+            await _unitOfWork.CompleteAsync();
 
             _logger.LogInformation("Customer {CustomerId} unsubscribed from email notifications via link", customer.Id);
 
@@ -88,9 +85,8 @@ public class UnsubscribeController : Controller
 
         try
         {
-            var company = await _context.Companies
-                .IgnoreQueryFilters()
-                .FirstOrDefaultAsync(c => c.MarketingUnsubscribeToken == token && !c.IsDeleted);
+            var company = await _unitOfWork.Companies.FirstOrDefaultAsync(
+                c => c.MarketingUnsubscribeToken == token && !c.IsDeleted, ignoreQueryFilters: true);
 
             if (company == null)
             {
@@ -105,7 +101,7 @@ public class UnsubscribeController : Controller
             {
                 company.MarketingEmailOptOut = true;
                 company.UpdatedAt = DateTime.UtcNow;
-                await _context.SaveChangesAsync();
+                await _unitOfWork.CompleteAsync();
                 _logger.LogInformation("Company {CompanyId} opted out of broadcast emails via link", company.Id);
             }