Add modal name popup when a Pi-Rat earns a Name

When a Pi-Rat completes their second objective and ranks up, they now
get a blocking modal popup (NameModal.svelte, rendered by Dashboard
across all phases) to claim their Pirate Name, rather than an optional
box buried in their character sheet. Removed the old inline prompt-box
and its handler from CharacterSheet.svelte.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/src/pages/Dashboard.svelte

@@ -16,6 +16,7 @@
     import RecruitPhase from '../components/RecruitPhase.svelte';
     import GameOverPhase from '../components/GameOverPhase.svelte';
     import EventLog from '../components/EventLog.svelte';
+    import NameModal from '../components/NameModal.svelte';
 
     export let params = {};
     let gameId = params.id;
@@ -210,6 +211,7 @@
     </div>
 
     <EventLog {state} />
+    <NameModal {state} />
 {:else if !error}
     <div class="loading-container">
         <p>Loading game state...</p>