fix: record type aliases now work for unification and field access

Expand type aliases via unify_with_env() everywhere in the type checker,
not just in a few places. This fixes named record types like
`type Vec2 = { x: Float, y: Float }` — they now properly unify with
anonymous records and support field access (v.x, v.y).

Also adds scripts/validate.sh for automated full-suite regression
testing (Rust tests + all 5 package test suites + type checking).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

scripts/release.sh

@@ -11,6 +11,10 @@ set -euo pipefail
 #   GITEA_TOKEN - API token for git.qrty.ink (prompted if not set)
 #   GITEA_URL   - Gitea instance URL (default: https://git.qrty.ink)
 
+# cd to repo root (directory containing this script's parent)
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+cd "$SCRIPT_DIR/.."
+
 GITEA_URL="${GITEA_URL:-https://git.qrty.ink}"
 REPO_OWNER="blu"
 REPO_NAME="lux"