feat(inventory): wire up v2 system to main panel with full interactivity

- Add inventory section to template.html between Thoughts and bottom controls
- Wire up renderInventory() to all event handlers (message received, character changed, swipes)
- Initialize inventory container reference and event listeners in index.js
- Add showInventory toggle checkbox to settings with visibility control
- Update layout.js to handle inventory section and divider visibility
- Add renderInventory parameter to updateRPGData for separate mode support
- Update state.js and config.js with inventory container and showInventory setting

Inventory is now fully integrated as a visible, interactive panel section that persists across all user interactions.

src/systems/generation/apiClient.js

@@ -25,8 +25,9 @@ import { parseResponse, parseUserStats } from './parser.js';
  * @param {Function} renderUserStats - UI function to render user stats
  * @param {Function} renderInfoBox - UI function to render info box
  * @param {Function} renderThoughts - UI function to render character thoughts
+ * @param {Function} renderInventory - UI function to render inventory
  */
-export async function updateRPGData(renderUserStats, renderInfoBox, renderThoughts) {
+export async function updateRPGData(renderUserStats, renderInfoBox, renderThoughts, renderInventory) {
     if (isGenerating) {
         // console.log('[RPG Companion] Already generating, skipping...');
         return;
@@ -123,6 +124,7 @@ export async function updateRPGData(renderUserStats, renderInfoBox, renderThough
                 renderUserStats();
                 renderInfoBox();
                 renderThoughts();
+                renderInventory();
             } else {
                 // No assistant message to attach to - just update display
                 if (parsedData.userStats) {
@@ -131,6 +133,7 @@ export async function updateRPGData(renderUserStats, renderInfoBox, renderThough
                 renderUserStats();
                 renderInfoBox();
                 renderThoughts();
+                renderInventory();
             }
 
             // Save to chat metadata