fix: remove legacy service dirs from setup_cell, update sanity_check for optional services

setup_cell.py no longer creates mail/radicale/webdav config and data dirs —
those are managed by ServiceComposer when services are installed. Added
data/services/ for ServiceComposer. sanity_check.py now uses stdlib urllib
and discovers installed services via /api/services/active before checking
their status routes.

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

scripts/setup_cell.py

@@ -19,26 +19,18 @@ REQUIRED_DIRS = [
     'config/dns',
     'config/dhcp',
     'config/ntp',
-    'config/mail/config',
-    'config/mail/ssl',
-    'config/radicale',
-    'config/webdav',
     'config/wireguard',
     'config/api',
     'data/caddy',
     'data/dns',
     'data/dhcp',
-    'data/maildata',
-    'data/mailstate',
-    'data/maillogs',
-    'data/radicale',
-    'data/files',
     'data/api',
     'data/vault/certs',
     'data/vault/keys',
     'data/vault/trust',
     'data/vault/ca',
     'data/logs',
+    'data/services',
     'data/wireguard/keys/peers',
     'data/wireguard/wg_confs',
 ]
@@ -47,8 +39,6 @@ REQUIRED_FILES = [
     'config/dns/Corefile',
     'config/dhcp/dnsmasq.conf',
     'config/ntp/chrony.conf',
-    'config/mail/mailserver.env',
-    'config/webdav/users.passwd',
 ]
 
 ROOT = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))