feat(services): initial config on ADD SERVICE — schema modal in DeckyCard, MazeNET drag, and Inspector

- DeckyServiceAddRequest gains an optional `config: dict` field, validated
  against the service's config_schema before any state mutation (400 on
  bad type, no half-written rows).
- Engine: add_service threads `config` into _add_topology_service /
  _add_fleet_service, persisting validated cfg to decky_config.service_config
  BEFORE compose regen so the first `up -d --build` materialises the env on
  the new container. No follow-up apply needed.
- Frontend: shared AddServiceConfigModal — same wizard accordion shape, used by:
    * DeckyCard's ADD SERVICE picker (Fleet & MazeNET inspectors via shared component)
    * MazeNET Inspector's ADD SERVICE picker
    * MazeNET palette drag-drop onto a deployed decky
  Empty-schema services short-circuit to a one-click add (no modal flash).
  Operator can cancel; errors surface in the modal.
- Tests: add_service config plumbing — persist, drop unknown keys, 400-equivalent
  on bad types, back-compat empty-config.
- Drive-by: fix stale repo-method names in test_services_live.py
  (create_topology_decky → add_topology_decky, get_topology_decky → list+pick helper,
  service.added → service_added topic).

decnet_web/src/components/MazeNET/Inspector.tsx

@@ -34,7 +34,10 @@ interface Props {
   // topologyStatus (active/degraded → live, pending/anything else →
   // design-time only).  Wiring these props from MazeNET.tsx is the
   // single switch that turns chips into live controls.
-  onLiveAddService?: (nodeName: string, slug: string) => Promise<void>;
+  /** Trigger the schema-driven add-service flow.  Synchronous: opens
+   *  the AddServiceConfigModal at the page level (or auto-confirms if
+   *  the service has no schema fields).  Errors surface inside the modal. */
+  onLiveAddService?: (nodeName: string, slug: string) => void;
   onLiveRemoveService?: (nodeName: string, slug: string) => Promise<void>;
   /** Per-decky-eligible service slugs, fetched via useServiceRegistry. */
   availableServices?: string[];
@@ -202,21 +205,15 @@ const Inspector: React.FC<Props> = ({
                     <button
                       type="button"
                       disabled={!addSlug || busy === addSlug}
-                      onClick={async () => {
+                      onClick={() => {
                         if (!addSlug) return;
                         setOpError(null);
-                        setBusy(addSlug);
-                        try {
-                          await onLiveAddService!(node.name, addSlug);
-                          setAddOpen(false);
-                          setAddSlug('');
-                        } catch (err) {
-                          const msg = (err as { response?: { data?: { detail?: string } } })?.response?.data?.detail
-                            ?? 'Add failed.';
-                          setOpError(msg);
-                        } finally {
-                          setBusy(null);
-                        }
+                        // Fire-and-forget: opens the schema-driven config
+                        // modal at the page level (or auto-confirms for
+                        // schema-less services). Errors surface in the modal.
+                        onLiveAddService!(node.name, addSlug);
+                        setAddOpen(false);
+                        setAddSlug('');
                       }}
                       style={{
                         padding: '4px 10px', fontSize: '0.7rem',