build(skill): add build:skill for a readable, non-bundled skill artifact (Phase 6)

`npm run build:skill` emits dist/obelisk-skill/: the whole scripts/ Core
compiled to readable JS (module structure + comments preserved, ~1:1 with
source, no bundling/minifying per ADR-0004), plus schema.sql, SKILL.md,
references/, and a package.json. It excludes app/, tests/, and release/, which
is what keeps the artifact small.

- tsconfig.skill.json compiles scripts/**/*.{ts,mjs} (allowJs) with
  rewriteRelativeImportExtensions, so the .ts specifiers inside the .mjs shells
  (runtime.mjs -> ./core.js, indexer.mjs -> ./providers/*.js, ./persist.js) are
  rewritten to .js. declaration:false — the skill needs no .d.ts.
- packaging/skill-package.json provides the artifact's package.json; it sets
  "type":"module" because the emitted .ts->.js files are ESM.
- build:skill runs tsc then copies schema.sql/SKILL.md/references/package.json.

Add tests/build-skill.test.mjs: runs the real build:skill, asserts the artifact
structure, that no emitted .js/.mjs still imports a .ts module, and that the
compiled artifact builds an index and answers a search end-to-end under plain
Node (no type-stripping) against a temp HOME.

Verified: suite 123/123, typecheck clean, artifact smoke run green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package.json

@@ -9,7 +9,8 @@
     "test": "node --experimental-test-module-mocks --test tests/*.test.mjs",
     "typecheck": "tsc --noEmit && tsc --noEmit -p app/tsconfig.json",
     "lint": "eslint .",
-    "build:core": "rm -rf dist && tsc -p tsconfig.build.json"
+    "build:core": "rm -rf dist && tsc -p tsconfig.build.json",
+    "build:skill": "rm -rf dist/obelisk-skill && tsc -p tsconfig.skill.json && cp scripts/schema.sql dist/obelisk-skill/scripts/ && cp SKILL.md dist/obelisk-skill/ && cp -R references dist/obelisk-skill/references && cp packaging/skill-package.json dist/obelisk-skill/package.json"
   },
   "devDependencies": {
     "@eslint/js": "^10.0.1",

packaging/skill-package.json

@@ -0,0 +1,7 @@
+{
+  "name": "obelisk-skill",
+  "version": "0.1.0",
+  "type": "module",
+  "description": "Obelisk skill artifact — readable compiled Core (providers + persist + runtime) over local Claude Code and Codex history. Built by `npm run build:skill`; sources live in the main repo.",
+  "license": "AGPL-3.0"
+}

tests/build-skill.test.mjs

@@ -0,0 +1,71 @@
+// Phase 6 acceptance: `npm run build:skill` must produce a runnable, readable,
+// .ts-free skill artifact under dist/obelisk-skill. This guards ADR-0004 (ship
+// readable non-bundled compiled JS) and catches import-rewriting / config drift
+// that would only surface when the installed skill runs under plain Node (no
+// type-stripping, no .ts resolution).
+import { test } from 'node:test';
+import assert from 'node:assert/strict';
+import { execFileSync, spawnSync } from 'node:child_process';
+import { readFileSync, readdirSync, mkdtempSync, mkdirSync, writeFileSync, rmSync, existsSync } from 'node:fs';
+import { tmpdir } from 'node:os';
+import { dirname, join, resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const repoRoot = resolve(dirname(fileURLToPath(import.meta.url)), '..');
+const skillDir = join(repoRoot, 'dist', 'obelisk-skill');
+
+function walk(dir) {
+  const out = [];
+  for (const entry of readdirSync(dir, { withFileTypes: true })) {
+    const full = join(dir, entry.name);
+    if (entry.isDirectory()) out.push(...walk(full));
+    else out.push(full);
+  }
+  return out;
+}
+
+test('build:skill produces a runnable, readable, .ts-free skill artifact', () => {
+  execFileSync('npm', ['run', 'build:skill'], { cwd: repoRoot, encoding: 'utf8', stdio: 'pipe' });
+
+  // Structure: compiled Core + copied .mjs + schema + docs + package.json.
+  for (const rel of [
+    'package.json', 'SKILL.md', 'references/api-reference.md',
+    'scripts/core.js', 'scripts/persist.js', 'scripts/providers/claude.js',
+    'scripts/providers/codex.js', 'scripts/runtime.mjs', 'scripts/indexer.mjs',
+    'scripts/db.mjs', 'scripts/parsing.mjs', 'scripts/query.mjs', 'scripts/schema.sql',
+  ]) {
+    assert.ok(existsSync(join(skillDir, rel)), `artifact missing ${rel}`);
+  }
+  assert.equal(JSON.parse(readFileSync(join(skillDir, 'package.json'), 'utf8')).type, 'module');
+
+  // Readable, not bundled: emitted files stay ~1:1 with source, and no relative
+  // import may still point at a .ts file (that would break under plain Node).
+  const jsFiles = walk(join(skillDir, 'scripts')).filter(f => f.endsWith('.js') || f.endsWith('.mjs'));
+  assert.ok(jsFiles.length >= 6, 'expected multiple un-bundled script files');
+  for (const file of jsFiles) {
+    const src = readFileSync(file, 'utf8');
+    assert.ok(!/from\s+['"][^'"]*\.ts['"]/.test(src), `${file} still imports a .ts module`);
+    assert.ok(!/import\(['"][^'"]*\.ts['"]\)/.test(src), `${file} still dynamic-imports a .ts module`);
+  }
+
+  // Runs end to end under plain Node against a fresh HOME (no type-stripping).
+  const home = mkdtempSync(join(tmpdir(), 'obelisk-skill-artifact-'));
+  try {
+    const projDir = join(home, '.claude', 'projects', '-tmp-proj');
+    mkdirSync(projDir, { recursive: true });
+    writeFileSync(join(projDir, 'smoke.jsonl'),
+      JSON.stringify({ uuid: 'm1', type: 'user', timestamp: '2026-06-10T10:00:00Z', cwd: '/tmp/proj', message: { role: 'user', content: 'hello artifact' } }) + '\n');
+    const env = { ...process.env, HOME: home };
+    const runtime = join(skillDir, 'scripts', 'runtime.mjs');
+
+    const build = spawnSync(process.execPath, [runtime, '--build'], { env, encoding: 'utf8' });
+    assert.equal(build.status, 0, build.stderr || build.stdout);
+
+    const search = spawnSync(process.execPath, [runtime, '--search', 'hello artifact'], { env, encoding: 'utf8' });
+    assert.equal(search.status, 0, search.stderr || search.stdout);
+    const hits = JSON.parse(search.stdout);
+    assert.equal(hits[0]?.message?.text, 'hello artifact', 'compiled artifact indexed and found the message');
+  } finally {
+    rmSync(home, { recursive: true, force: true });
+  }
+});

tsconfig.skill.json

@@ -0,0 +1,11 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    "noEmit": false,
+    "outDir": "dist/obelisk-skill/scripts",
+    "rootDir": "scripts",
+    "declaration": false,
+    "rewriteRelativeImportExtensions": true
+  },
+  "include": ["scripts/**/*.ts", "scripts/**/*.mjs"]
+}