feat: Add --all flag to estimate command to list available configs

- Added find_configs_directory() to use same logic as API (api/configs_repo/official first, then configs/)
- Added list_all_configs() to display all 24 configs grouped by category with descriptions
- Updated CLI to support --all flag, making config argument optional when --all is used
- Added 2 new tests for --all flag functionality
- All 51 tests passing (51 passed, 1 skipped)

This enables users to discover all available preset configs without checking the API or filesystem directly.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

tests/test_estimate_pages.py

@@ -134,6 +134,60 @@ class TestEstimatePagesCLI(unittest.TestCase):
         except FileNotFoundError:
             self.skipTest("skill-seekers command not installed")
 
+    def test_cli_all_flag_lists_configs(self):
+        """Test that --all flag lists all available configs"""
+        import subprocess
+
+        try:
+            # Run with --all flag
+            result = subprocess.run(
+                ['skill-seekers', 'estimate', '--all'],
+                capture_output=True,
+                text=True,
+                timeout=10
+            )
+
+            # Should succeed
+            self.assertEqual(result.returncode, 0)
+
+            # Should contain expected output
+            output = result.stdout
+            self.assertIn('AVAILABLE CONFIGS', output)
+            self.assertIn('Total:', output)
+            self.assertIn('configs found', output)
+
+            # Should list some known configs
+            # (these should exist in api/configs_repo/official/)
+            self.assertTrue(
+                'react' in output.lower() or
+                'django' in output.lower() or
+                'godot' in output.lower(),
+                "Expected at least one known config name in output"
+            )
+        except FileNotFoundError:
+            self.skipTest("skill-seekers command not installed")
+
+    def test_cli_all_flag_with_direct_entry_point(self):
+        """Test --all flag works with skill-seekers-estimate entry point"""
+        import subprocess
+
+        try:
+            result = subprocess.run(
+                ['skill-seekers-estimate', '--all'],
+                capture_output=True,
+                text=True,
+                timeout=10
+            )
+
+            # Should succeed
+            self.assertEqual(result.returncode, 0)
+
+            # Should show available configs
+            output = result.stdout
+            self.assertIn('AVAILABLE CONFIGS', output)
+        except FileNotFoundError:
+            self.skipTest("skill-seekers-estimate command not installed")
+
 
 class TestEstimatePagesWithRealConfig(unittest.TestCase):
     """Test estimation with real config files (if available)"""