Fix MCP indicator source resolution

[saleh-mir]

Summary

• resolve indicator details from exported functions instead of assuming function names match filenames
• filter package-module attributes out of list_indicators
• correct MCP stochastic examples to use the public stoch name

This fixes details lookup for:

• stoch
• support_resistance_with_breaks
• waddah_attar_explosion

Verification

• all 174 indicators returned by list_indicators resolve successfully
• direct registered MCP wrapper calls pass for all three mismatched names
• 33 MCP tests pass
• 178 indicator tests pass
• Python compilation and git diff --check pass

Note: pytest plugin auto-loading was disabled because this environment has an unrelated incompatible AnyIO pytest plugin (_pytest.scope import error). No packages were changed.