feat: chat avatars + dark theme fix + text overflow fix

Avatars:
- Robot icon (green circle) before each agent message
- Person icon (dark circle) before each user message
- New .chat-bubble wrapper with flex layout for avatar + message

Dark theme fixes:
- Panel background: #1e1e1e (not pure black)
- Agent bubbles: #2d2d2d with light text (not dark/invisible)
- Input area: #2d2d2d (not black)
- Header stays green (--accent-green) in both themes
- Chips, suggestions consistent with panel background

Text overflow:
- overflow-wrap + word-break on messages
- min-width: 0 prevents flex overflow
- User bubble properly right-aligned with avatar

internal/chat/handler.go

@@ -222,14 +222,14 @@ func (h *Handler) HandleChat(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// User message bubble
-	_, _ = fmt.Fprintf(w, `<div class="chat-message chat-user">%s</div>`, html.EscapeString(message))
+	// User message bubble with avatar
+	_, _ = fmt.Fprintf(w, `<div class="chat-bubble chat-user"><div class="chat-avatar chat-avatar-user"><iconify-icon icon="mdi:account"></iconify-icon></div><div class="chat-message">%s</div></div>`, html.EscapeString(message))
 
-	// Agent response bubble
+	// Agent response bubble with avatar
 	if response == "" {
 		response = "I couldn't find an answer to that. Try asking about experience, projects, skills, or education."
 	}
-	_, _ = fmt.Fprintf(w, `<div class="chat-message chat-agent">%s</div>`, formatResponse(response))
+	_, _ = fmt.Fprintf(w, `<div class="chat-bubble chat-bot"><div class="chat-avatar chat-avatar-bot"><iconify-icon icon="mdi:robot-happy-outline"></iconify-icon></div><div class="chat-message">%s</div></div>`, formatResponse(response))
 
 	// Session ID via OOB swap
 	_, _ = fmt.Fprintf(w, `<input type="hidden" id="chat-session-id" name="session_id" value="%s" form="chat-form" hx-swap-oob="true"/>`, sessionID)