Fix ecosystem grid to 3 columns for balanced 3x2 layout

The auto-fit minmax(200px) was creating 5 columns, causing module
path text overflow and an orphaned 6th card. Fixed to repeat(3, 1fr)
which gives a clean 3+3 grid matching the 6 ecosystem modules.

Author: dndungu

index.html

@@ -139,7 +139,8 @@
 
 /* Ecosystem */
 .eco{background:var(--bg)}
-.eco-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px}
+.eco-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}
+@media(max-width:768px){.eco-grid{grid-template-columns:1fr}}
 .eco-card{display:block;background:var(--bg2);border:1px solid rgba(255,255,255,.06);border-radius:10px;padding:24px 20px;transition:border-color .2s}
 .eco-card:hover{border-color:rgba(6,182,212,.3)}
 .eco-card .mod{font-family:var(--mono);font-size:.8125rem;color:var(--cyan);margin-bottom:8px}