fix startup packaging and content guardrails

tests/skill-paths.test.ts

@@ -0,0 +1,28 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { existsSync, readdirSync, readFileSync } from "node:fs";
+import { dirname, join, resolve } from "node:path";
+import { fileURLToPath } from "node:url";
+
+const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
+const skillsRoot = join(repoRoot, "skills");
+const markdownPathPattern = /`((?:\.\.?\/)(?:[A-Za-z0-9._-]+\/)*[A-Za-z0-9._-]+\.md)`/g;
+const simulatedInstallRoot = join(repoRoot, "__skill-install-root__");
+
+test("all local markdown references in bundled skills resolve in the installed skill layout", () => {
+	for (const entry of readdirSync(skillsRoot, { withFileTypes: true })) {
+		if (!entry.isDirectory()) continue;
+
+		const skillPath = join(skillsRoot, entry.name, "SKILL.md");
+		if (!existsSync(skillPath)) continue;
+
+		const content = readFileSync(skillPath, "utf8");
+		for (const match of content.matchAll(markdownPathPattern)) {
+			const reference = match[1];
+			const installedSkillDir = join(simulatedInstallRoot, entry.name);
+			const installedTarget = resolve(installedSkillDir, reference);
+			const repoTarget = installedTarget.replace(simulatedInstallRoot, repoRoot);
+			assert.ok(existsSync(repoTarget), `${skillPath} references missing installed markdown file ${reference}`);
+		}
+	}
+});