refactor: consolidate project loading into EntityGrid component

Unify project loading and searching logic in EntityGrid.vue to eliminate
duplication. Make entities prop optional for projects, add internal
project state, and auto-load projects when needed.

- EntityGrid: Combine search/load into fetchProjects(), add internal
  allProjects state, handle pagination internally for both search and
  load modes
- OnboardMeetingSetupView: Remove project loading methods
- MeetingProjectDialog: Remove project props
- GiftedDialog: Remove project loading logic
- EntitySelectionStep: Make projects prop optional

Reduces code duplication by ~150 lines and simplifies component APIs.
All project selection now uses EntityGrid's internal loading.

src/components/EntitySelectionStep.vue

@@ -14,7 +14,7 @@ properties * * @author Matthew Raymer */
 
     <EntityGrid
       :entity-type="shouldShowProjects ? 'projects' : 'people'"
-      :entities="shouldShowProjects ? projects : allContacts"
+      :entities="shouldShowProjects ? projects || undefined : allContacts"
       :active-did="activeDid"
       :all-my-dids="allMyDids"
       :all-contacts="allContacts"
@@ -23,7 +23,6 @@ properties * * @author Matthew Raymer */
       :you-selectable="youSelectable"
       :notify="notify"
       :conflict-context="conflictContext"
-      :load-more-callback="shouldShowProjects ? loadMoreCallback : undefined"
       @entity-selected="handleEntitySelected"
     />
 
@@ -95,9 +94,9 @@ export default class EntitySelectionStep extends Vue {
   @Prop({ default: false })
   isFromProjectView!: boolean;
 
-  /** Array of available projects */
-  @Prop({ required: true })
-  projects!: PlanData[];
+  /** Array of available projects (optional - EntityGrid loads internally if not provided) */
+  @Prop({ required: false })
+  projects?: PlanData[];
 
   /** Array of available contacts */
   @Prop({ required: true })
@@ -149,10 +148,6 @@ export default class EntitySelectionStep extends Vue {
   @Prop()
   notify?: (notification: NotificationIface, timeout?: number) => void;
 
-  /** Callback function to load more projects from server */
-  @Prop()
-  loadMoreCallback?: (entities: PlanData[]) => Promise<void>;
-
   /**
    * CSS classes for the cancel button
    */