fix: remove unused validation percentage indicator

The 0% indicator next to the Run button was not providing useful
feedback. Removed from HTML, CSS, and app.js.

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.html

@@ -47,7 +47,6 @@
 										<button id="redo-btn" class="btn btn-icon" title="Redo (Ctrl+Shift+Z)">↷</button>
 										<button id="reset-code-btn" class="btn btn-icon" title="Reset to initial code">⟲</button>
 									</div>
-									<div class="validation-indicators-container"></div>
 									<button id="run-btn" class="btn btn-run">
 										<img src="./gear.svg" alt="" />Run
 									</button>