[bug] lore catalog: validate explicit --kind override before import

[kunallanjewar]

Summary

lore catalog DIR --kind <kind> accepts the --kind flag without validating that the value belongs to the accepted kind taxonomy (idea, research, decision, observation, principle). An invalid kind propagates into the corpus and corrupts downstream filtering / search.

Affected files

• internal/lore/catalog.go
• internal/lore/catalog_cmd.go (line 15)

Reproduction

guild lore catalog ./somepath --kind not-a-real-kind

Observed: entries land with kind="not-a-real-kind".
Expected: command errors with the valid kinds enumerated.

Acceptance

• Catalog rejects unknown --kind values up-front.
• Error message lists valid options.
• Default (no override) behavior unchanged.