Declarative flows already used `module:qualname` refs for runtime
objects, but crew JSON tools still had their own lookup path. That meant
examples like `project_tools:LookupTool` were treated as named
`crewai_tools` lookups and failed with guidance that only mentioned
`SerperDevTool` or `custom:<name>`. Invalid refs such as
`not_tools:NotATool` also missed the same BaseTool validation used by
flow tool actions.
Move ref resolution into a shared declarative helper, use it from flow
tool actions and crew JSON loading, and require tool refs to resolve to
`BaseTool` classes before instantiation. Validation still checks tool
refs structurally, so validating a crew does not import or execute
project code.
7738a1d30c