fix(installer): harden release asset resolution (#1258)

Co-authored-by: Jwalin Shah <jshah1331@gmail.com>

scripts/test_install.sh

@@ -0,0 +1,33 @@
+#!/usr/bin/env bash
+# scripts/test_install.sh — smoke-tests the install.sh resolver in isolation.
+set -euo pipefail
+
+REPO_ROOT="$(cd "$(dirname "$0")/.." && pwd)"
+
+# Use a fixture latest.json that mirrors what the real release publishes.
+FIXTURE="$REPO_ROOT/scripts/fixtures/latest.json"
+
+# The resolver function should be sourced, not invoked end-to-end (no curl).
+if ! source "$REPO_ROOT/scripts/install.sh" --source-only 2>/dev/null; then
+  echo "FAIL: scripts/install.sh does not support --source-only mode"
+  exit 1
+fi
+
+resolved=$(resolve_asset_url "$FIXTURE" "linux" "x86_64")
+expected="https://example.invalid/openhuman_0.0.0-test_amd64.AppImage"
+if [[ "$resolved" != "$expected" ]]; then
+  echo "FAIL: expected $expected, got $resolved"
+  exit 1
+fi
+
+# Also test a missing platform produces exit code 3.
+set +e
+resolve_asset_url "$FIXTURE" "linux" "aarch64" >/dev/null 2>&1
+missing_platform_rc=$?
+set -e
+if [[ "$missing_platform_rc" -ne 3 ]]; then
+  echo "FAIL: expected exit code 3 for missing platform linux-aarch64, got $missing_platform_rc"
+  exit 1
+fi
+
+echo "PASS"