fix: Remove non-existent valuation_formula property from portfolio page

frontend/src/app/command/portfolio/page.tsx

@@ -705,10 +705,6 @@ export default function PortfolioPage() {
                     {valuation.confidence}
                   </span>
                 </div>
-                <div className="p-3 bg-foreground/5 rounded-lg">
-                  <p className="text-foreground-muted mb-1">Valuation Formula</p>
-                  <p className="text-foreground font-mono text-xs break-all">{valuation.valuation_formula}</p>
-                </div>
                 <div className="p-3 bg-amber-400/10 border border-amber-400/20 rounded-lg text-xs text-amber-400">
                   <p>This is an algorithmic estimate based on domain length, TLD, and market patterns. Actual market value may vary.</p>
                 </div>