Migrate 25 route files to throw-based error handling

Converted routes:
- All auth routes (totp.js, keys.js, sso-gate.js)
- Recipe deployment routes (deploy.js, manage.js, index.js)
- App deployment routes
- Config routes (assets, backup, settings)
- ARR routes (config, credentials)
- Infrastructure routes (dns, services, sites, logs)
- Additional routes (browse, ca, health, license, notifications, tailscale, updates)

Changes:
- Replaced ctx.errorResponse() with throw statements
- Replaced errorResponse() with throw statements
- Added proper error imports to each file
- 400 errors → ValidationError
- 401 errors → AuthenticationError
- 403 errors → ForbiddenError
- 404 errors → NotFoundError
- 409 errors → ConflictError
- 500 errors → Handled by middleware

Result: 25 files migrated, ~150 error responses standardized

dashcaddy-api/routes/recipes/manage.js

@@ -1,5 +1,6 @@
 const express = require('express');
 const { DOCKER } = require('../../constants');
+const { NotFoundError } = require('../../errors');
 
 module.exports = function(ctx) {
   const router = express.Router();
@@ -96,7 +97,7 @@ module.exports = function(ctx) {
     const containers = await findRecipeContainers(recipeId);
 
     if (containers.length === 0) {
-      return ctx.errorResponse(res, 404, 'No containers found for this recipe');
+      throw new NotFoundError('Containers for recipe');
     }
 
     const results = [];
@@ -127,7 +128,7 @@ module.exports = function(ctx) {
     const containers = await findRecipeContainers(recipeId);
 
     if (containers.length === 0) {
-      return ctx.errorResponse(res, 404, 'No containers found for this recipe');
+      throw new NotFoundError('Containers for recipe');
     }
 
     const results = [];
@@ -159,7 +160,7 @@ module.exports = function(ctx) {
     const containers = await findRecipeContainers(recipeId);
 
     if (containers.length === 0) {
-      return ctx.errorResponse(res, 404, 'No containers found for this recipe');
+      throw new NotFoundError('Containers for recipe');
     }
 
     const results = [];
@@ -185,7 +186,7 @@ module.exports = function(ctx) {
     const containers = await findRecipeContainers(recipeId);
 
     if (containers.length === 0) {
-      return ctx.errorResponse(res, 404, 'No containers found for this recipe');
+      throw new NotFoundError('Containers for recipe');
     }
 
     ctx.log.info('recipe', 'Removing recipe', { recipeId, containerCount: containers.length });