Round out the index discovery so the lazy toolbox boots against the full
shipping tool set:
- ``scripts/tool_source/_discover.py`` now handles ``<tool_dir>`` panel
entries and reads YAML tool ids alongside XML, so multi-version tool
directories and YAML tools land in the index.
- ``LazyToolBox`` extends the bootstrap path to register every variant
discovered for a single tool id (was previously dropping siblings) and
uses the shared YAML id reader when chasing direct ``<tool file=...>``
references from the panel config.
- ``DatabaseToolSourceStore.store_index`` accepts the richer per-id
payload from the discovery script.
Test coverage is extended in ``test_tool_source_storage`` to assert that
the bootstrapped index sees both directory-based and YAML-defined tools.
mvdbeek
af2fa367e8