feat: quote detail modal, SteelERP favicon, and notification navigation

- Pipeline page: clicking a supplier quote card opens a modal with full
  line-item breakdown, lead time, payment terms, notes, awarded status,
  and a Compare All Quotes button
- Eager-load supplierQuotes.supplier and supplierQuotes.items in pipeline
  controller to avoid N+1 on the modal data
- Browser tab now shows SteelERP first (SteelERP — Page Name)
- Added SVG favicon matching the sidebar blue-square logo
- Notification clicks now navigate to the relevant page via a dedicated
  /notifications/{id}/go route that marks only that notification as read

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

public/favicon.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 32 32">
+  <rect width="32" height="32" rx="7" fill="#0f172a"/>
+  <rect x="4" y="4" width="24" height="24" rx="5" fill="#2563eb"/>
+  <text x="16" y="23" font-family="Arial Black, Arial, sans-serif" font-weight="900" font-size="18" fill="#ffffff" text-anchor="middle" letter-spacing="-1">S</text>
+</svg>