Migrate to Symfony framework

config/packages/framework.yaml

+# see https://symfony.com/doc/current/reference/configuration/framework.html
+framework:
+    secret: '%env(APP_SECRET)%'
+    #csrf_protection: true
+    #http_method_override: true
+
+    # Enables session support. Note that the session will ONLY be started if you read or write from it.
+    # Remove or comment this section to explicitly disable session support.
+    session:
+        handler_id: null
+        cookie_secure: auto
+        cookie_samesite: lax
+
+    #esi: true
+    #fragments: true
+    php_errors:
+        log: true

config/packages/mailer.yaml

+framework:
+    mailer:
+        dsn: '%env(MAILER_DSN)%'

config/packages/notifier.yaml

+framework:
+    notifier:
+        #chatter_transports:
+        #    slack: '%env(SLACK_DSN)%'
+        #    telegram: '%env(TELEGRAM_DSN)%'
+        #texter_transports:
+        #    twilio: '%env(TWILIO_DSN)%'
+        #    nexmo: '%env(NEXMO_DSN)%'
+        channel_policy:
+            # use chat/slack, chat/telegram, sms/twilio or sms/nexmo
+            urgent: ['email']
+            high: ['email']
+            medium: ['email']
+            low: ['email']
+        admin_recipients:
+            - { email: admin@example.com }

config/packages/prod/deprecations.yaml

+# As of Symfony 5.1, deprecations are logged in the dedicated "deprecation" channel when it exists
+#monolog:
+#    channels: [deprecation]
+#    handlers:
+#        deprecation:
+#            type: stream
+#            channels: [deprecation]
+#            path: "%kernel.logs_dir%/%kernel.environment%.deprecations.log"

config/packages/prod/doctrine.yaml

+doctrine:
+    orm:
+        auto_generate_proxy_classes: false
+        metadata_cache_driver:
+            type: pool
+            pool: doctrine.system_cache_pool
+        query_cache_driver:
+            type: pool
+            pool: doctrine.system_cache_pool
+        result_cache_driver:
+            type: pool
+            pool: doctrine.result_cache_pool
+
+framework:
+    cache:
+        pools:
+            doctrine.result_cache_pool:
+                adapter: cache.app
+            doctrine.system_cache_pool:
+                adapter: cache.system

config/packages/prod/monolog.yaml

+monolog:
+    handlers:
+        main:
+            type: fingers_crossed
+            action_level: error
+            handler: nested
+            excluded_http_codes: [404, 405]
+            buffer_size: 50 # How many messages should be saved? Prevent memory leaks
+        nested:
+            type: stream
+            path: "%kernel.logs_dir%/%kernel.environment%.log"
+            level: debug
+        console:
+            type: console
+            process_psr_3_messages: false
+            channels: ["!event", "!doctrine"]

config/packages/prod/routing.yaml

+framework:
+    router:
+        strict_requirements: null

config/packages/prod/webpack_encore.yaml

+#webpack_encore:
+    # Cache the entrypoints.json (rebuild Symfony's cache when entrypoints.json changes)
+    # Available in version 1.2
+    #cache: true

config/packages/routing.yaml

+framework:
+    router:
+        utf8: true
+
+        # Configure how to generate URLs in non-HTTP contexts, such as CLI commands.
+        # See https://symfony.com/doc/current/routing.html#generating-urls-in-commands
+        #default_uri: http://localhost

config/packages/security.yaml

+security:
+    enable_authenticator_manager: true
+    # https://symfony.com/doc/current/security.html#registering-the-user-hashing-passwords
+    password_hashers:
+        Symfony\Component\Security\Core\User\PasswordAuthenticatedUserInterface: 'auto'
+    # https://symfony.com/doc/current/security.html#loading-the-user-the-user-provider
+    providers:
+        users_in_memory: { memory: null }
+    firewalls:
+        dev:
+            pattern: ^/(_(profiler|wdt)|css|images|js)/
+            security: false
+        main:
+            lazy: true
+            provider: users_in_memory
+
+            # activate different ways to authenticate
+
+            # https://symfony.com/doc/current/security/impersonating_user.html
+            # switch_user: true
+
+    # Easy way to control access for large sections of your site
+    # Note: Only the *first* access control that matches will be used
+    access_control:
+        # - { path: ^/admin, roles: ROLE_ADMIN }
+        # - { path: ^/profile, roles: ROLE_USER }
+
+    encoders:
+        # this internal class is used by Symfony to represent in-memory users
+        Symfony\Component\Security\Core\User\User: 'auto'

config/packages/sensio_framework_extra.yaml

+sensio_framework_extra:
+    router:
+        annotations: false

config/packages/test/framework.yaml

+framework:
+    test: true
+    session:
+        storage_id: session.storage.mock_file

config/packages/test/monolog.yaml

+monolog:
+    handlers:
+        main:
+            type: fingers_crossed
+            action_level: error
+            handler: nested
+            excluded_http_codes: [404, 405]
+            channels: ["!event"]
+        nested:
+            type: stream
+            path: "%kernel.logs_dir%/%kernel.environment%.log"
+            level: debug

config/packages/test/twig.yaml

+twig:
+    strict_variables: true

config/packages/test/validator.yaml

+framework:
+    validation:
+        not_compromised_password: false

config/packages/test/web_profiler.yaml

+web_profiler:
+    toolbar: false
+    intercept_redirects: false
+
+framework:
+    profiler: { collect: false }

config/packages/test/webpack_encore.yaml

+#webpack_encore:
+#    strict_mode: false

config/packages/translation.yaml

+framework:
+    default_locale: en
+    translator:
+        default_path: '%kernel.project_dir%/translations'
+        fallbacks:
+            - en

config/packages/twig.yaml

+twig:
+    default_path: '%kernel.project_dir%/templates'

config/packages/validator.yaml

+framework:
+    validation:
+        email_validation_mode: html5
+
+        # Enables validator auto-mapping support.
+        # For instance, basic validation constraints will be inferred from Doctrine's metadata.
+        #auto_mapping:
+        #    App\Entity\: []