Add before/after demo video (CASA, pre-migration)

casa_old.mp4 records CASA's UI before it was migrated onto a design system,
for a visual before/after alongside this repo's written evidence trail.
Re-encoded from the original ~112MB capture (H.264 CRF 18) to fit under
GitHub's 100MB file-size limit -- the rubyforgood org has Git LFS disabled
org-wide, so this ships as a normal tracked file rather than an LFS pointer.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: giacoelho

.gitignore

@@ -1,3 +1,4 @@
 node_modules/
 __pycache__/
 *.pyc
+.DS_Store

videos/README.md

@@ -0,0 +1,7 @@
+# Videos
+
+- **`casa_old.mp4`** — a recording of [CASA](https://github.com/rubyforgood/casa) before its UI
+  was migrated onto a design system, kept as before/after reference material alongside this
+  system's docs. Re-encoded from the original ~112MB capture (H.264 CRF 18, faststart) to fit
+  under GitHub's 100MB file-size limit; the `rubyforgood` org has Git LFS disabled, so this is a
+  normal tracked file rather than an LFS pointer.