feat: add skill-seekers doctor health check command (#316)

8 diagnostic checks: Python version (3.10+), package install, git,
14 core deps, 10 optional deps, API keys, MCP server, output dir.
Each check reports pass/warn/fail with --verbose for extra detail.
Exit code 0 if no critical failures, 1 otherwise.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/test_doctor.py

@@ -0,0 +1,164 @@
+"""Tests for skill-seekers doctor command (#316)."""
+
+from __future__ import annotations
+
+import os
+from unittest.mock import patch
+
+from skill_seekers.cli.doctor import (
+    CheckResult,
+    check_api_keys,
+    check_core_deps,
+    check_git,
+    check_mcp_server,
+    check_optional_deps,
+    check_output_directory,
+    check_package_installed,
+    check_python_version,
+    print_report,
+    run_all_checks,
+)
+
+
+class TestCheckPythonVersion:
+    def test_passes_on_current_python(self):
+        result = check_python_version()
+        assert result.status == "pass"
+        assert result.critical is True
+
+    def test_detail_contains_version(self):
+        result = check_python_version()
+        assert "." in result.detail  # e.g. "3.14.3"
+
+
+class TestCheckPackageInstalled:
+    def test_passes_when_installed(self):
+        result = check_package_installed()
+        assert result.status == "pass"
+        assert result.detail.startswith("v")
+
+    def test_fails_when_import_broken(self):
+        with (
+            patch.dict("sys.modules", {"skill_seekers._version": None}),
+            patch("builtins.__import__", side_effect=ImportError("mocked")),
+        ):
+            result = check_package_installed()
+            assert result.status == "fail"
+
+
+class TestCheckGit:
+    def test_passes_when_git_available(self):
+        result = check_git()
+        # Most CI/dev environments have git
+        assert result.status in ("pass", "warn")
+
+    def test_warns_when_git_missing(self):
+        with patch("skill_seekers.cli.doctor.shutil.which", return_value=None):
+            result = check_git()
+            assert result.status == "warn"
+
+
+class TestCheckCoreDeps:
+    def test_passes_in_normal_environment(self):
+        result = check_core_deps()
+        assert result.status == "pass"
+        assert result.critical is True
+
+    def test_detail_shows_count(self):
+        result = check_core_deps()
+        assert "found" in result.detail.lower() or "missing" in result.detail.lower()
+
+
+class TestCheckOptionalDeps:
+    def test_returns_result(self):
+        result = check_optional_deps()
+        assert result.status in ("pass", "warn")
+        assert "/" in result.detail  # e.g. "7/10 installed"
+
+
+class TestCheckApiKeys:
+    def test_warns_when_no_keys(self):
+        with patch.dict(os.environ, {}, clear=True):
+            result = check_api_keys()
+            assert result.status == "warn"
+
+    def test_passes_when_all_set(self):
+        env = {
+            "ANTHROPIC_API_KEY": "sk-ant-test123456789",
+            "GITHUB_TOKEN": "ghp_test123456789",
+            "GOOGLE_API_KEY": "AIza_test123456789",
+            "OPENAI_API_KEY": "sk-test123456789",
+        }
+        with patch.dict(os.environ, env, clear=True):
+            result = check_api_keys()
+            assert result.status == "pass"
+
+    def test_partial_keys_warns(self):
+        env = {"ANTHROPIC_API_KEY": "sk-ant-test123456789"}
+        with patch.dict(os.environ, env, clear=True):
+            result = check_api_keys()
+            assert result.status == "warn"
+            assert "1 set" in result.detail
+
+
+class TestCheckMcpServer:
+    def test_returns_result(self):
+        result = check_mcp_server()
+        assert result.status in ("pass", "warn")
+
+
+class TestCheckOutputDirectory:
+    def test_passes_in_writable_dir(self):
+        result = check_output_directory()
+        assert result.status == "pass"
+        assert result.critical is True
+
+
+class TestRunAllChecks:
+    def test_returns_8_results(self):
+        results = run_all_checks()
+        assert len(results) == 8
+
+    def test_all_have_name_and_status(self):
+        results = run_all_checks()
+        for r in results:
+            assert isinstance(r, CheckResult)
+            assert r.name
+            assert r.status in ("pass", "warn", "fail")
+
+
+class TestPrintReport:
+    def test_returns_0_when_no_failures(self, capsys):
+        results = [
+            CheckResult("Test1", "pass", "ok", critical=True),
+            CheckResult("Test2", "warn", "meh"),
+        ]
+        code = print_report(results)
+        assert code == 0
+        captured = capsys.readouterr()
+        assert "1 passed" in captured.out
+        assert "1 warnings" in captured.out
+
+    def test_returns_1_when_critical_failure(self, capsys):
+        results = [
+            CheckResult("Test1", "pass", "ok"),
+            CheckResult("Test2", "fail", "broken", critical=True),
+        ]
+        code = print_report(results)
+        assert code == 1
+
+    def test_verbose_shows_detail(self, capsys):
+        results = [
+            CheckResult("Test1", "pass", "ok", verbose_detail="  extra: info"),
+        ]
+        print_report(results, verbose=True)
+        captured = capsys.readouterr()
+        assert "extra: info" in captured.out
+
+    def test_no_verbose_hides_detail(self, capsys):
+        results = [
+            CheckResult("Test1", "pass", "ok", verbose_detail="  secret: hidden"),
+        ]
+        print_report(results, verbose=False)
+        captured = capsys.readouterr()
+        assert "secret: hidden" not in captured.out