set GH_REPO for CCfW (#22993)

Co-authored-by: Brent Westbrook <36778786+ntBre@users.noreply.github.com>

.claude/hooks/session-start-web.sh

@@ -7,6 +7,11 @@ if ! command -v gh &> /dev/null; then
     apt-get install -y -qq gh
 fi
 
+# Set GH_REPO so `gh` works even when the git remote points to a local proxy
+if [ -n "${CLAUDE_ENV_FILE:-}" ]; then
+  echo 'export GH_REPO=astral-sh/ruff' >> "$CLAUDE_ENV_FILE"
+fi
+
 # Install clippy and rustfmt for the active toolchain.
 rustup component add clippy rustfmt