Fix Claude Code CLI detection for npm-local installs

`specify check` reports "Claude Code CLI (not found)" for users who
installed Claude Code via npm-local (the default installer path, common
with nvm). The binary lives at ~/.claude/local/node_modules/.bin/claude
which was not checked. Add CLAUDE_NPM_LOCAL_PATH as a second well-known
location alongside the existing migrate-installer path.

Fixes #550

Author: one-kash

src/specify_cli/__init__.py

@@ -345,6 +345,7 @@ def _build_ai_assistant_help() -> str:
 SCRIPT_TYPE_CHOICES = {"sh": "POSIX Shell (bash/zsh)", "ps": "PowerShell"}
 
 CLAUDE_LOCAL_PATH = Path.home() / ".claude" / "local" / "claude"
+CLAUDE_NPM_LOCAL_PATH = Path.home() / ".claude" / "local" / "node_modules" / ".bin" / "claude"
 
 BANNER = """
 ███████╗██████╗ ███████╗ ██████╗██╗███████╗██╗   ██╗
@@ -605,13 +606,16 @@ def check_tool(tool: str, tracker: StepTracker = None) -> bool:
     Returns:
         True if tool is found, False otherwise
     """
-    # Special handling for Claude CLI after `claude migrate-installer`
+    # Special handling for Claude CLI local installs
     # See: https://github.com/github/spec-kit/issues/123
-    # The migrate-installer command REMOVES the original executable from PATH
-    # and creates an alias at ~/.claude/local/claude instead
-    # This path should be prioritized over other claude executables in PATH
+    # See: https://github.com/github/spec-kit/issues/550
+    # Claude Code can be installed in two local paths:
+    #   1. ~/.claude/local/claude          (after `claude migrate-installer`)
+    #   2. ~/.claude/local/node_modules/.bin/claude  (npm-local install, e.g. via nvm)
+    # Neither path may be on the system PATH, so we check them explicitly.
     if tool == "claude":
-        if CLAUDE_LOCAL_PATH.exists() and CLAUDE_LOCAL_PATH.is_file():
+        if (CLAUDE_LOCAL_PATH.exists() and CLAUDE_LOCAL_PATH.is_file()) or \
+           (CLAUDE_NPM_LOCAL_PATH.exists() and CLAUDE_NPM_LOCAL_PATH.is_file()):
             if tracker:
                 tracker.complete(tool, "available")
             return True

tests/test_check_tool.py

@@ -0,0 +1,95 @@
+"""Tests for check_tool() — Claude Code CLI detection across install methods.
+
+Covers issue https://github.com/github/spec-kit/issues/550:
+  `specify check` reports "Claude Code CLI (not found)" even when claude is
+  installed via npm-local (the default `claude` installer path).
+"""
+
+from pathlib import Path
+from unittest.mock import patch, MagicMock
+
+import pytest
+
+from specify_cli import check_tool
+
+
+class TestCheckToolClaude:
+    """Claude CLI detection must work for all install methods."""
+
+    def test_detected_via_migrate_installer_path(self, tmp_path):
+        """claude migrate-installer puts binary at ~/.claude/local/claude."""
+        fake_claude = tmp_path / "claude"
+        fake_claude.touch()
+
+        with patch("specify_cli.CLAUDE_LOCAL_PATH", fake_claude), \
+             patch("shutil.which", return_value=None):
+            assert check_tool("claude") is True
+
+    def test_detected_via_npm_local_path(self, tmp_path):
+        """npm-local install puts binary at ~/.claude/local/node_modules/.bin/claude."""
+        fake_npm_claude = tmp_path / "node_modules" / ".bin" / "claude"
+        fake_npm_claude.parent.mkdir(parents=True)
+        fake_npm_claude.touch()
+
+        # Neither the migrate-installer path nor PATH has claude
+        fake_migrate = tmp_path / "nonexistent" / "claude"
+
+        with patch("specify_cli.CLAUDE_LOCAL_PATH", fake_migrate), \
+             patch("specify_cli.CLAUDE_NPM_LOCAL_PATH", fake_npm_claude), \
+             patch("shutil.which", return_value=None):
+            assert check_tool("claude") is True
+
+    def test_detected_via_path(self):
+        """claude on PATH (global npm install) should still work."""
+        fake_missing = Path("/nonexistent/claude")
+
+        with patch("specify_cli.CLAUDE_LOCAL_PATH", fake_missing), \
+             patch("specify_cli.CLAUDE_NPM_LOCAL_PATH", fake_missing), \
+             patch("shutil.which", return_value="/usr/local/bin/claude"):
+            assert check_tool("claude") is True
+
+    def test_not_found_when_nowhere(self):
+        """Should return False when claude is genuinely not installed."""
+        fake_missing = Path("/nonexistent/claude")
+
+        with patch("specify_cli.CLAUDE_LOCAL_PATH", fake_missing), \
+             patch("specify_cli.CLAUDE_NPM_LOCAL_PATH", fake_missing), \
+             patch("shutil.which", return_value=None):
+            assert check_tool("claude") is False
+
+    def test_tracker_updated_on_npm_local_detection(self, tmp_path):
+        """StepTracker should be marked 'available' for npm-local installs."""
+        fake_npm_claude = tmp_path / "node_modules" / ".bin" / "claude"
+        fake_npm_claude.parent.mkdir(parents=True)
+        fake_npm_claude.touch()
+
+        fake_missing = Path("/nonexistent/claude")
+        tracker = MagicMock()
+
+        with patch("specify_cli.CLAUDE_LOCAL_PATH", fake_missing), \
+             patch("specify_cli.CLAUDE_NPM_LOCAL_PATH", fake_npm_claude), \
+             patch("shutil.which", return_value=None):
+            result = check_tool("claude", tracker=tracker)
+
+        assert result is True
+        tracker.complete.assert_called_once_with("claude", "available")
+
+
+class TestCheckToolOther:
+    """Non-Claude tools should be unaffected by the fix."""
+
+    def test_git_detected_via_path(self):
+        with patch("shutil.which", return_value="/usr/bin/git"):
+            assert check_tool("git") is True
+
+    def test_missing_tool(self):
+        with patch("shutil.which", return_value=None):
+            assert check_tool("nonexistent-tool") is False
+
+    def test_kiro_fallback(self):
+        """kiro-cli detection should try both kiro-cli and kiro."""
+        def fake_which(name):
+            return "/usr/bin/kiro" if name == "kiro" else None
+
+        with patch("shutil.which", side_effect=fake_which):
+            assert check_tool("kiro-cli") is True