Recent changes to the IconLink column component renamed iconCls to cellIconCls. The LinkedIn column was still using the old property name, causing a regression where the LinkedIn icon wouldn't render.

Additionally, the Twitter (X) column in the DevIndex grid was rendering raw usernames as href values instead of full URLs.

Changes:

• src/grid/column/LinkedIn.mjs: Updated iconCls to cellIconCls to match the underlying IconLink component.
• apps/devindex/view/home/GridContainer.mjs: Added a urlFormatter to the Twitter column to properly format the X link (e.g. https://x.com/[username]).