Doctor validator does not expand ${ENV_VAR} in script: paths before checking file existence #191

Summary

OrgLoop's orgloop doctor validator checks whether a script: path exists on disk but does not expand environment variable references (e.g. ${ORGLOOP_PROJECT_ROOT}) before calling stat/access. This causes a false-positive failure even when the file is present and the env var is set correctly.

Repro

1. Set ORGLOOP_PROJECT_ROOT=/path/to/project in .env
2. Define a transform with script: ${ORGLOOP_PROJECT_ROOT}/scripts/my-script.sh
3. Confirm the file exists at the resolved path
4. Run orgloop doctor (with or without source .env) → reports Script not found: ${ORGLOOP_PROJECT_ROOT}/scripts/my-script.sh

Expected

Doctor expands env var references in script: paths before checking existence, matching how the daemon resolves them at runtime.

Impact

• orgloop doctor exits non-zero and blocks orgloop start (without --force)
• Workaround: orgloop start --force — runtime works correctly because the daemon expands env vars properly
• The on_error: pass safety net also means the transform passes events through if the script is truly missing, so this is validator-only noise