Tighten workflow preset community smoke

[bigsmartben]

Summary

• Build the community smoke CLI from the PR checkout as a wheel, then install from that wheel before running specify init.
• Assert the installed workflow-preset manifest and preset registry both report 1.3.1 and match each other.
• Strengthen extension remove/re-add smoke coverage so stale Claude skill files cannot satisfy reinstall checks.
• Harden local PowerShell test harness behavior for WSL/Windows PowerShell environments that cannot see git or preserve POSIX modes.

Test Plan

• uv run --python 3.11 --extra test pytest -s -q tests/test_presets.py::TestBundledPresetLocator::test_workflow_preset_catalog_matches_manifest tests/test_presets.py::TestBundledPresetLocator::test_community_smoke_checks_wheel_assets_and_extension_dev_reinstall tests/integrations/test_cli.py::TestGitExtensionAutoInstall::test_workflow_preset_registers_commands_and_composes_wrappers
• uv run --python 3.11 --extra test pytest -s tests/test_setup_plan_feature_json.py tests/test_setup_tasks.py tests/test_setup_arch.py -q
• uv run --python 3.11 --extra test pytest -s tests/integrations/test_cli.py -q
• uv run --python 3.11 --extra test pytest -s
• local wheel smoke: build wheel, install wheel, run specify init, assert manifest/registry workflow-preset version 1.3.1
• git diff --check