Remove chat empty-state splash screen — duplicates welcome message

[amiable-dev]

Description

When the GUI first loads, a splash screen with a large 💬 emoji and "No messages yet. Start a conversation!" appears in the chat panel before the actual welcome message loads. This is unnecessary and creates a flash of content — the proper welcome message ("Welcome to Conductor Chat! I can help you configure your MIDI controller...") renders shortly after once chatStore.initialize() completes.

Root Cause

ChatView.svelte has two competing empty-state presentations:

1. Empty state splash (lines 465-469) — renders immediately

{#if messages.length === 0}
  <div class="empty-state">
    <div class="empty-icon">💬</div>
    <p>No messages yet. Start a conversation!</p>
  </div>

2. Welcome message (lines 376-385) — renders after async init

onMount(async () => {
  await chatStore.initialize(); // async — takes time
  if (!$hasMessages) {
    chatStore.addSystemMessage('Welcome to Conductor Chat! ...');
  }
});

The empty state renders while initialize() is in progress, then gets replaced by the welcome message once it completes. This creates a visible flash of the splash emoji before the real content appears.

Recommendation

Remove the empty-state splash block entirely (lines 465-469 and CSS at lines 793-807). The welcome addSystemMessage() already handles the empty state properly. If a loading indicator is needed during initialize(), show a subtle spinner rather than a splash with an emoji.

Priority

P4 — Visual flash on startup, no functional impact.

Acceptance Criteria

• No 💬 emoji splash screen shown on initial load
• Welcome message ("Welcome to Conductor Chat!...") is the first content shown
• No flash of intermediate content before the welcome message
• If initialize() takes time, either show nothing or a subtle loading indicator (not a splash)
• Returning to an empty chat (e.g., after deleting all conversations) shows the welcome message, not the splash