fix(llm-dialog): when re-creating schema via source cell, follow cell path

[seefeldb]

Summary by cubic

Fix schema resolution in llm-dialog when deriving a cell’s schema from a source cell. We now follow the cell’s path in the source schema so nested outputs get the correct schema.

• Bug Fixes
  • Derive schema from the source cell’s resultRef and the current cell path using schemaAtPath.
  • Keep fallback to a minimal schema when no source schema is available.
  • Update schemaAtPath to accept a readonly string[] path.

^{Written for commit dd531b2. Summary will update automatically on new commits.}

[cubic-dev-ai]

No issues found across 2 files