feat: Phase 6 — require_active_service decorator + wizard install wiring

Email/calendar/files routes now return 404 when the service is not
installed, using a require_active_service decorator that checks
ServiceRegistry. Status endpoints are exempt so health checks always work.

SetupManager.complete_setup() now accepts a service_store_manager and
installs any wizard-selected services in a background daemon thread after
setup completes. Failures are logged but do not fail the wizard.

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

api/routes/calendar.py

@@ -1,9 +1,12 @@
 import logging
 from flask import Blueprint, request, jsonify
+from routes import require_active_service
+
 logger = logging.getLogger('picell')
 bp = Blueprint('calendar', __name__)
 
 @bp.route('/api/calendar/users', methods=['GET'])
+@require_active_service('calendar')
 def get_calendar_users():
     """Get calendar users."""
     try:
@@ -15,6 +18,7 @@ def get_calendar_users():
         return jsonify({"error": str(e)}), 500
 
 @bp.route('/api/calendar/users', methods=['POST'])
+@require_active_service('calendar')
 def create_calendar_user():
     """Create calendar user."""
     try:
@@ -33,6 +37,7 @@ def create_calendar_user():
         return jsonify({"error": str(e)}), 500
 
 @bp.route('/api/calendar/users/<username>', methods=['DELETE'])
+@require_active_service('calendar')
 def delete_calendar_user(username):
     """Delete calendar user."""
     try:
@@ -44,6 +49,7 @@ def delete_calendar_user(username):
         return jsonify({"error": str(e)}), 500
 
 @bp.route('/api/calendar/calendars', methods=['POST'])
+@require_active_service('calendar')
 def create_calendar():
     """Create calendar."""
     try:
@@ -67,6 +73,7 @@ def create_calendar():
         return jsonify({"error": str(e)}), 500
 
 @bp.route('/api/calendar/events', methods=['POST'])
+@require_active_service('calendar')
 def add_calendar_event():
     try:
         from app import calendar_manager
@@ -85,6 +92,7 @@ def add_calendar_event():
         return jsonify({"error": str(e)}), 500
 
 @bp.route('/api/calendar/events/<username>/<calendar_name>', methods=['GET'])
+@require_active_service('calendar')
 def get_calendar_events(username, calendar_name):
     """Get calendar events."""
     try:
@@ -108,6 +116,7 @@ def get_calendar_status():
         return jsonify({"error": str(e)}), 500
 
 @bp.route('/api/calendar/connectivity', methods=['GET'])
+@require_active_service('calendar')
 def test_calendar_connectivity():
     """Test calendar connectivity."""
     try: