The PR-built wheel + import smoke gate refused the platform_tools
package because it's a new subdirectory under workspace/ that wasn't
in scripts/build_runtime_package.py:SUBPACKAGES. The drift gate (which
exists for exactly this reason) caught it cleanly:
error: SUBPACKAGES drifted from workspace/ subdirectories:
in workspace/ but NOT in SUBPACKAGES (will ship un-rewritten or
be excluded): ['platform_tools']
Adding platform_tools to SUBPACKAGES wires the package into the
runtime wheel + applies the canonical
from platform_tools.<x> -> from molecule_runtime.platform_tools.<x>
import-rewrite step that every other subpackage uses.
Verified locally: scripts/build_runtime_package.py succeeds, the
rewritten a2a_mcp_server.py reads
from molecule_runtime.platform_tools.registry import TOOLS
which matches the package layout in the wheel.