fix(web): restore 3-column NPC chat modal layout for desktop

- Fixed grid layout not applying to modal content (grid was on wrong parent element)
- Applied grid to .npc-chat-container instead of .npc-modal-body--three-col
- Removed htmx-indicator class from history panel (was causing content to disappear)
- Made history loading indicator visible by default
- Updated responsive breakpoints to target correct selectors
- Added warning to HTMX_PATTERNS.md about htmx-indicator hidden behavior

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

public_web/docs/HTMX_PATTERNS.md

@@ -564,6 +564,8 @@ def create_character():
 <span id="spinner" class="htmx-indicator">⏳</span>
 ```
 
+> **IMPORTANT:** The `htmx-indicator` class is **hidden by default** (opacity: 0) and only shown during active requests. Never put this class on a container that should remain visible - only use it on loading spinners/messages that should appear during requests and disappear after.
+
 ### 4. Debounce Search Inputs
 ```html
 <input hx-get="/search"
@@ -646,6 +648,6 @@ document.body.addEventListener('htmx:responseError', (event) => {
 
 ---
 
-**Document Version:** 1.1
+**Document Version:** 1.2
 **Created:** November 18, 2025
-**Last Updated:** November 21, 2025
+**Last Updated:** November 26, 2025