Migrate Auth/Contractor/Document/Notification/Subscription services to ctx

Every public method on these five services now takes ctx context.Context as
the first arg and routes its repo calls through .WithContext(ctx). With
TaskService and ResidenceService already migrated, this means every
in-process service that touches Postgres now produces a flame graph in
Jaeger where the SQL spans nest under the parent HTTP request span.

Endpoints now fully traced (HTTP → service → SQL):
- /api/auth/login, /register, /logout, /me, /verify-email, /resend-verification
- /api/auth/forgot-password, /verify-reset, /reset-password, /update-profile
- /api/contractors/* (CRUD + favorite + by-residence + tasks)
- /api/documents/* (CRUD + activate/deactivate + image upload/delete)
- /api/notifications/* (list, count, mark-read, prefs, devices)
- /api/subscription/* (status, purchase, cancel, triggers, promotions)
- All previously-migrated /api/tasks/* and /api/residences/* paths

Internal helpers also threaded:
- TaskService.sendTaskCompletedNotification → forwards ctx
- TaskService.UpdateUserTimezone → forwards ctx to NotificationService
- ResidenceService.CreateResidence → forwards ctx to SubscriptionService.CheckLimit
- NotificationService.registerAPNSDevice / registerGCMDevice → both take ctx

~75 method signatures, ~120 handler/test call sites updated. Tests pass
green; the only failure is the pre-existing flaky TaskHandler_QuickComplete
SQLite race that fails ~60% of runs on master.

Step 3 of the observability plan is now genuinely complete: every API
endpoint backed by a Go service emits a per-request flame graph with
HTTP → service → SQL spans, plus B2/APNs/FCM/asynq spans where applicable.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/services/subscription_service_test.go

@@ -1,6 +1,7 @@
 package services
 
 import (
+	"context"
 	"testing"
 	"time"
 
@@ -70,7 +71,7 @@ func TestProcessApplePurchase_ClientNil_ReturnsError(t *testing.T) {
 		googleClient:     nil,
 	}
 
-	_, err := svc.ProcessApplePurchase(user.ID, "fake-receipt", "")
+	_, err := svc.ProcessApplePurchase(context.Background(), user.ID, "fake-receipt", "")
 	assert.Error(t, err, "ProcessApplePurchase should return error when Apple IAP client is nil")
 
 	// Verify user was NOT upgraded to Pro
@@ -109,7 +110,7 @@ func TestProcessApplePurchase_ValidationFails_DoesNotUpgrade(t *testing.T) {
 	}
 
 	// Neither receipt data nor transaction ID - should still not grant Pro
-	_, err := svc.ProcessApplePurchase(user.ID, "", "")
+	_, err := svc.ProcessApplePurchase(context.Background(), user.ID, "", "")
 	assert.Error(t, err, "ProcessApplePurchase should return error when client is nil, even with empty data")
 
 	// Verify no upgrade happened
@@ -140,7 +141,7 @@ func TestProcessGooglePurchase_ClientNil_ReturnsError(t *testing.T) {
 		googleClient:     nil, // Not configured
 	}
 
-	_, err := svc.ProcessGooglePurchase(user.ID, "fake-token", "com.tt.honeyDue.pro.monthly")
+	_, err := svc.ProcessGooglePurchase(context.Background(), user.ID, "fake-token", "com.tt.honeyDue.pro.monthly")
 	assert.Error(t, err, "ProcessGooglePurchase should return error when Google IAP client is nil")
 
 	// Verify user was NOT upgraded to Pro
@@ -172,7 +173,7 @@ func TestProcessGooglePurchase_ValidationFails_DoesNotUpgrade(t *testing.T) {
 	}
 
 	// With empty token
-	_, err := svc.ProcessGooglePurchase(user.ID, "", "")
+	_, err := svc.ProcessGooglePurchase(context.Background(), user.ID, "", "")
 	assert.Error(t, err, "ProcessGooglePurchase should return error when client is nil")
 
 	// Verify no upgrade happened
@@ -202,7 +203,7 @@ func TestSubscriptionService_GetSubscription(t *testing.T) {
 
 	user := testutil.CreateTestUser(t, db, "owner", "owner@test.com", "Password123")
 
-	resp, err := svc.GetSubscription(user.ID)
+	resp, err := svc.GetSubscription(context.Background(), user.ID)
 	require.NoError(t, err)
 	assert.Equal(t, "free", resp.Tier)
 	assert.False(t, resp.IsPro)
@@ -238,7 +239,7 @@ func TestSubscriptionService_GetSubscription_ProUser(t *testing.T) {
 	err := db.Create(sub).Error
 	require.NoError(t, err)
 
-	resp, err := svc.GetSubscription(user.ID)
+	resp, err := svc.GetSubscription(context.Background(), user.ID)
 	require.NoError(t, err)
 	assert.Equal(t, "pro", resp.Tier)
 	assert.True(t, resp.IsPro)
@@ -277,7 +278,7 @@ func TestSubscriptionService_CancelSubscription(t *testing.T) {
 	err := db.Create(sub).Error
 	require.NoError(t, err)
 
-	resp, err := svc.CancelSubscription(user.ID)
+	resp, err := svc.CancelSubscription(context.Background(), user.ID)
 	require.NoError(t, err)
 	assert.False(t, resp.AutoRenew)
 }
@@ -365,7 +366,7 @@ func TestIsAlreadyProFromOtherPlatform(t *testing.T) {
 			err := db.Create(sub).Error
 			require.NoError(t, err)
 
-			conflict, existingPlatform, err := svc.IsAlreadyProFromOtherPlatform(user.ID, tt.requestedPlatform)
+			conflict, existingPlatform, err := svc.IsAlreadyProFromOtherPlatform(context.Background(), user.ID, tt.requestedPlatform)
 			require.NoError(t, err)
 			assert.Equal(t, tt.wantConflict, conflict)
 			assert.Equal(t, tt.wantPlatform, existingPlatform)