feat: retain visual test artifacts on failure

- Updated `playwright.config.ts` to use separate projects for 'visual' and 'e2e' tests.
- Configured 'visual' project to retain screenshots, traces, and videos on failure.
- Set Playwright output directory to `artifacts/test-results`.
- Added `scripts/show-artifacts.sh` to help locate test artifacts.
- Updated `KNOWN_ISSUES.md` and `README.md` with debugging instructions.

scripts/show-artifacts.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+# script to show artifacts
+ARTIFACTS_DIR="artifacts/test-results"
+
+if [ -d "$ARTIFACTS_DIR" ]; then
+  echo "Artifacts located in $ARTIFACTS_DIR"
+  echo "Listing contents:"
+  ls -F "$ARTIFACTS_DIR"
+else
+  echo "No artifacts found in $ARTIFACTS_DIR"
+fi