fix: correct endpoint selection for streamable HTTP auto-registration

[ABruneel04]

Description

Summary

Fixes auto-registration endpoint selection when using --expose-streamable-http flag. The system was incorrectly attempting to register at the /sse endpoint instead of /mcp for Streamable HTTP connections.

Problem

When running cforge run with the --expose-streamable-http flag, auto-registration failed with a 404 error because the system attempted to register at the /sse endpoint, which doesn't exist for Streamable HTTP servers.

Solution

Updated the boolean logic in cforge/commands/server/run.py to correctly determine the endpoint type:

Before:

is_sse = expose_sse or expose_streamable_http or (not expose_sse and not expose_streamable_http)

After:

is_sse = expose_sse or not expose_streamable_http

This ensures:

• When only --expose-streamable-http is enabled → uses /mcp endpoint
• When only --expose-sse is enabled → uses /sse endpoint
• When both flags are enabled → defaults to /sse endpoint (SSE takes priority)
• When neither flag is specified → defaults to /sse endpoint

Testing

Added comprehensive test coverage for all endpoint selection scenarios:

• test_run_registration_with_streamable_http_only - Verifies /mcp endpoint is used when only streamable HTTP is enabled
• test_run_registration_with_both_protocols_defaults_to_sse - Verifies SSE takes priority when both protocols are enabled
• test_run_registration_without_protocol_flags_defaults_to_sse - Verifies SSE is the default when no flags are specified

Live Testing: Tested end-to-end with the original failing command to confirm the fix resolves the auto-registration issue.

Changes

• Modified cforge/commands/server/run.py - Fixed endpoint selection logic
• Added 94 lines of test coverage in tests/commands/server/test_run.py

Closes

Closes #27

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update

Checklist

• My code follows the style guidelines of this project (Black, isort, Ruff, Pylint)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (if applicable)
• My changes generate no new warnings
• I have added tests that prove my fix is effective
• New and existing unit tests pass locally with my changes
• I have signed my commits with DCO (git commit -s)