feat: Add discoverable 'analyze' subcommand with preset flags (Phase 1 UX improvement)

Implements Phase 1 of the codebase analysis UX improvement plan, making the
command discoverable and adding intuitive preset flags while maintaining 100%
backward compatibility.

New Features:
- Add 'analyze' subcommand to main CLI (skill-seekers analyze)
- Add --quick preset: Fast analysis (1-2 min, basic features only)
- Add --comprehensive preset: Full analysis (20-60 min, all features + AI)
- Add --enhance flag: Simple AI enhancement with auto-detection
- Improve help text with timing estimates and mode descriptions

Files Modified:
- src/skill_seekers/cli/main.py: Add analyze subcommand (lines 15, 273-311, 542-589)
- src/skill_seekers/cli/codebase_scraper.py: Add preset logic and improve help text
- tests/test_analyze_command.py: NEW - 20 comprehensive tests
- tests/test_cli_paths.py: Fix version check (2.7.0 -> 2.7.2)
- tests/test_package_structure.py: Fix 4 version checks (2.7.0 -> 2.7.2)
- README.md: Update examples to use 'analyze' command
- CLAUDE.md: Update examples to use 'analyze' command

Test Results:
- 81 tests related to Phase 1: ALL PASSING ✅
- 20 new tests for analyze command: ALL PASSING ✅
- Zero regressions introduced
- 100% backward compatibility maintained

Backward Compatibility:
- Old 'skill-seekers-codebase' command still works
- All existing flags (--depth, --ai-mode, --skip-*) still functional
- No breaking changes

Usage Examples:
  skill-seekers analyze --directory . --quick
  skill-seekers analyze --directory . --comprehensive
  skill-seekers analyze --directory . --enhance

Fixes #262 (codebase UX issues)

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

tests/test_cli_paths.py

@@ -138,7 +138,7 @@ class TestUnifiedCLIEntryPoints(unittest.TestCase):
 
             # Should show version
             output = result.stdout + result.stderr
-            self.assertIn("2.7.0", output)
+            self.assertIn("2.7.2", output)
 
         except FileNotFoundError:
             # If skill-seekers is not installed, skip this test