test: lite E2E coverage for benchmark, taste engine, publish

Fills real coverage gaps in v0.19.0.0 primitives. 44 new deterministic
tests (gate tier, ~3s) + 8 live-API tests (periodic tier).

New gate-tier test files (free, <3s total):
- test/taste-engine.test.ts — 24 tests against gstack-taste-update:
  schema shape, Laplace-smoothed confidence, 5%/week decay clamped at 0,
  multi-dimension extraction, case-insensitive matching, session cap,
  legacy profile migration with session truncation, taste-drift conflict
  warning, malformed-JSON recovery, missing-variant exit code.
- test/publish-dry-run.test.ts — 13 tests against gstack-publish --dry-run:
  manifest parsing, missing/malformed JSON, per-skill validation errors
  (missing source file / slug / version / marketplaces), slug filter,
  unknown-skill exit, per-marketplace auth isolation (fake marketplaces
  with always-pass / always-fail / missing-binary CLIs), and a sanity
  check against the real repo manifest.
- test/benchmark-cli.test.ts — 11 tests against gstack-model-benchmark
  --dry-run: provider default, unknown-provider WARN, empty list
  fallback, flag passthrough (timeout/workdir/judge/output), long-prompt
  truncation, prompt resolution (inline vs file vs positional), missing
  prompt exit.

New periodic-tier test file (paid, gated EVALS=1):
- test/skill-e2e-benchmark-providers.test.ts — 8 tests hitting real
  claude, codex, gemini CLIs with a trivial prompt (~$0.001/provider).
  Verifies output parsing, token accounting, cost estimation, timeout
  error.code semantics, Promise.allSettled parallel isolation.
  Per-provider availability gate — unauthed providers skip cleanly.

This suite already caught one real bug (codex adapter missing
--skip-git-repo-check, fixed in 5260987d).

Registered `benchmark-providers-live` in touchfiles.ts (periodic tier,
triggered by changes to bin/gstack-model-benchmark, providers/**,
benchmark-runner.ts, pricing.ts).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

test/benchmark-cli.test.ts

@@ -0,0 +1,134 @@
+/**
+ * gstack-model-benchmark CLI tests (offline).
+ *
+ * Covers CLI wiring that unit tests against benchmark-runner.ts can't see:
+ *   - --dry-run auth/provider-list resolution
+ *   - unknown provider WARN path
+ *   - provider default (claude) when --models omitted
+ *   - prompt resolution (inline --prompt vs positional file path)
+ *   - output format flag wiring via --dry-run (avoids real CLI invocation)
+ *
+ * All tests use --dry-run so no API calls happen.
+ */
+
+import { describe, test, expect } from 'bun:test';
+import { spawnSync } from 'child_process';
+import * as fs from 'fs';
+import * as path from 'path';
+import * as os from 'os';
+
+const ROOT = path.resolve(import.meta.dir, '..');
+const BIN = path.join(ROOT, 'bin', 'gstack-model-benchmark');
+
+function run(args: string[], opts: { env?: Record<string, string> } = {}): { status: number | null; stdout: string; stderr: string } {
+  const result = spawnSync('bun', ['run', BIN, ...args], {
+    cwd: ROOT,
+    env: { ...process.env, ...opts.env },
+    encoding: 'utf-8',
+    timeout: 15000,
+  });
+  return {
+    status: result.status,
+    stdout: result.stdout?.toString() ?? '',
+    stderr: result.stderr?.toString() ?? '',
+  };
+}
+
+describe('gstack-model-benchmark --dry-run', () => {
+  test('prints provider availability report and exits 0', () => {
+    const r = run(['--prompt', 'hi', '--models', 'claude,gpt,gemini', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('gstack-model-benchmark --dry-run');
+    expect(r.stdout).toContain('claude');
+    expect(r.stdout).toContain('gpt');
+    expect(r.stdout).toContain('gemini');
+    expect(r.stdout).toContain('no prompts sent');
+  });
+
+  test('reports default provider when --models omitted', () => {
+    const r = run(['--prompt', 'hi', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('providers:  claude');
+  });
+
+  test('unknown provider in --models emits WARN and is dropped', () => {
+    const r = run(['--prompt', 'hi', '--models', 'claude,gpt-42-fake', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stderr).toContain('unknown provider');
+    expect(r.stderr).toContain('gpt-42-fake');
+    expect(r.stdout).toContain('providers:  claude');
+    expect(r.stdout).not.toContain('gpt-42-fake');
+  });
+
+  test('empty --models list falls back to claude default', () => {
+    const r = run(['--prompt', 'hi', '--models', '', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('providers:  claude');
+  });
+
+  test('--timeout-ms and --workdir flags flow through to dry-run report', () => {
+    const r = run(['--prompt', 'hi', '--timeout-ms', '9999', '--workdir', '/tmp', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('timeout_ms: 9999');
+    expect(r.stdout).toContain('workdir:    /tmp');
+  });
+
+  test('--judge flag reported in dry-run output', () => {
+    const r = run(['--prompt', 'hi', '--judge', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('judge:      on');
+  });
+
+  test('--output flag reported in dry-run', () => {
+    const r = run(['--prompt', 'hi', '--output', 'json', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('output:     json');
+  });
+
+  test('each adapter reports either OK or NOT READY, never crashes', () => {
+    const r = run(['--prompt', 'hi', '--models', 'claude,gpt,gemini', '--dry-run']);
+    expect(r.status).toBe(0);
+    // Each provider line must end in OK or NOT READY
+    const lines = r.stdout.split('\n');
+    const adapterLines = lines.filter(l => /^\s+(claude|gpt|gemini):/.test(l));
+    expect(adapterLines.length).toBe(3);
+    for (const line of adapterLines) {
+      expect(line).toMatch(/(OK|NOT READY)/);
+    }
+  });
+
+  test('long prompt is truncated in dry-run display', () => {
+    const longPrompt = 'x'.repeat(200);
+    const r = run(['--prompt', longPrompt, '--dry-run']);
+    expect(r.status).toBe(0);
+    // Summary truncates to 80 chars + ellipsis
+    expect(r.stdout).toMatch(/prompt:\s+x{80}…/);
+  });
+});
+
+describe('gstack-model-benchmark prompt resolution', () => {
+  test('positional file path is read and passed as prompt', () => {
+    const tmp = fs.mkdtempSync(path.join(os.tmpdir(), 'bench-prompt-'));
+    const promptFile = path.join(tmp, 'prompt.txt');
+    fs.writeFileSync(promptFile, 'hello from file');
+    try {
+      const r = run([promptFile, '--dry-run']);
+      expect(r.status).toBe(0);
+      expect(r.stdout).toContain('hello from file');
+    } finally {
+      fs.rmSync(tmp, { recursive: true, force: true });
+    }
+  });
+
+  test('positional non-file arg is treated as inline prompt', () => {
+    const r = run(['treat-me-as-inline', '--dry-run']);
+    expect(r.status).toBe(0);
+    expect(r.stdout).toContain('treat-me-as-inline');
+  });
+
+  test('missing prompt exits non-zero', () => {
+    const r = run(['--dry-run']);
+    expect(r.status).not.toBe(0);
+    expect(r.stderr).toContain('specify a prompt');
+  });
+});