test(visual): commit baseline snapshots for regression testing

- Remove e2e/visual-snapshots/ from .gitignore so baselines are tracked
- Generate baseline screenshots across desktop/tablet/mobile and chromium/firefox/webkit
- Total: 95 snapshots (~114MB) covering 12 pages and component states

NOTE: Consider migrating to Git LFS if snapshot history grows too large.

.gitignore

@@ -287,8 +287,8 @@ findings.md
 # ============================================================
 # IMPORTANT NOTES
 # ============================================================
-# Visual regression snapshots should be committed to version control
-# These are in: e2e/src/tests/visual/**/*-snapshots/
+# Visual regression snapshots are committed to version control
+# These are in: e2e/visual-snapshots/
 # Git will track them because they are not in test-results/ or allure-results/
 
 # AGENTS
@@ -304,7 +304,7 @@ dogfood-bain/
 .superpowers/brainstorm/
 
 # test outputs
-e2e/visual-snapshots/
+# NOTE: visual regression baselines are intentionally tracked; see IMPORTANT NOTES above
 responsive-test/
 visual-test/
 tests/screenshots/