feat(FR-1368): add deployment launcher — multi-step form, hook, page, and deploy split buttons (#6912)

Resolves #6912

## Summary

Consolidates the full deployment launcher UX (FR-2674, FR-2683, FR-2675, FR-2684):

- **FR-2674**: `DeploymentLauncherPageContent` — multi-step form (Basic → Resources → Review) with nuqs URL state, pre-fill support, and per-step validation
- **FR-2683**: `useDeploymentLauncher` hook — encapsulates Quick Deploy (`deployInstantly`) and launcher navigation (`openLauncher`) using `createModelDeployment`; gated behind `model-deployment-extended-filter` flag
- **FR-2675**: `DeploymentLauncherPage` — page-level orchestrator for `/deployments/new` (create) and `/deployments/:id/edit` routes; owns the `createModelDeployment` / `addModelRevision` mutations
- **FR-2684**: Migrate Deploy buttons in `ModelCardDrawer` and `VFolderDeployModal` to `[Deploy | ▼]` split button using `useDeploymentLauncher`; dropdown opens pre-filled launcher at the review step

Author: agatha197

data/schema.graphql

@@ -46,10 +46,13 @@ const BAIProjectResourceGroupSelect: React.FC<
 
   const { resourceGroups } = useProjectResourceGroups(projectName, { filter });
 
-  // If the current selected value is not in the resourceGroups, reset the value to undefined
+  // If the loaded resource group list does not contain the current value, reset to undefined.
+  // Guard on resourceGroups.length > 0 so we don't wipe a pre-filled value while the list
+  // is still loading — an empty list means "not yet fetched", not "no valid groups".
   useEffect(() => {
     if (
       controllableValue &&
+      resourceGroups.length > 0 &&
       !_.some(resourceGroups, (item) => item.name === controllableValue)
     ) {
       setControllableValueWithTransition(undefined);
@@ -68,18 +71,17 @@ const BAIProjectResourceGroupSelect: React.FC<
     : undefined;
 
   useEffect(() => {
-    if (
-      autoSelectDefault &&
-      autoSelectedOption &&
-      autoSelectedOption.value !== selectProps.value
-    ) {
+    if (autoSelectDefault && autoSelectedOption && !controllableValue) {
       setControllableValueWithTransition(
         autoSelectedOption.value,
         autoSelectedOption,
       );
     }
+    // controllableValue is intentionally excluded from deps — we only want
+    // to fire when the available options first appear (autoSelectedOption?.value
+    // transitions from undefined→name), not on every selection change.
     // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [autoSelectDefault]);
+  }, [autoSelectDefault, autoSelectedOption?.value]);
 
   return (
     <BAISelect

packages/backend.ai-ui/src/components/BAIProjectResourceGroupSelect.tsx

@@ -55,6 +55,7 @@ export const useProjectResourceGroups = (
   projectName: string,
   options?: UseProjectResourceGroupsOptions,
 ) => {
+  'use memo';
   const baiRequestWithPromise = useBAISignedRequestWithPromise();
 
   const { data } = useSuspenseTanQuery<ProjectResourceGroupsQueryResult>({