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/components/scene/CharacterSheet.svelte

@@ -5,7 +5,6 @@
     export let state;
 
     let error = '';
-    let newNameInput = '';
     let pvpOpponentId = '';
     let pvpCard = '';
 
@@ -21,19 +20,6 @@
     // What the chosen duel card becomes as a temporary Obstacle for the defender
     $: pvpCardObstacle = cardObstacleInfo(pvpCard, $obstacleTable);
 
-    async function submitNewName() {
-        if (!newNameInput.trim()) return;
-        error = '';
-        try {
-            await apiRequest(`/game/${state.game.id}/player/${state.player.id}/set-name`, 'POST', {
-                new_name: newNameInput.trim()
-            });
-            newNameInput = '';
-        } catch(e) {
-            error = e.message;
-        }
-    }
-
     async function createPvp() {
         error = '';
         try {
@@ -83,17 +69,6 @@
             </div>
         {/if}
 
-        {#if state.player.needs_name}
-            <div class="prompt-box accent">
-                <h4>🏴‍☠️ You Earned a Name!</h4>
-                <p class="info-text" style="margin-bottom: 0.5rem;">You completed your second objective and ranked up! What is your new Pirate Name?</p>
-                <div class="input-row">
-                    <input type="text" bind:value={newNameInput} class="input-field" placeholder="Enter new name...">
-                    <button class="btn btn-gold" on:click={submitNewName} disabled={!newNameInput.trim()}>Claim Name</button>
-                </div>
-            </div>
-        {/if}
-
         {#if state.player.tax_banned}
             <div class="prompt-box danger text-center">
                 <p class="info-text" style="margin: 0; font-size: 0.9rem;">🚫 You failed a refused Tax — no more Gat/Name Taxes for you this scene.</p>