fix(react): detect job-attachment paths across all union branches

[cotovanu-cristian]

Summary

get_json_paths_by_type is documented to return JSONPaths for all fields that reference a
given type. It silently misses every path when a field is a genuine multi-branch union and the
target type is not the first non-None member.

The cause is in _recursive_search: it called _unwrap_optional(annotation), which collapses any
Union to its first non-None member. So Union[str, Target], Union[A, Target],
Optional[Union[A, Target]], list[Union[A, Target]], the PEP-604 form str | Target | None, and
a union whose member nests the target type all reduced to the first branch — the rest were never
searched, the function returned [], and downstream extract_values_by_paths silently dropped the
value (e.g. a job attachment).

This matters in normal operation: a JSON-schema field {"anyOf": [{"type": "string"}, {"$ref": ".../job-attachment"}]} becomes Union[str, <Attachment>, None], so a real attachment passed in a
string-or-attachment field was never resolved.

The contract

The function's own docstring: "Get JSONPath expressions for all fields that reference a
specific type … recursively traverses nested Pydantic models to find all paths." A field
reachable via any union member references that type, so its path must be returned. Union/Optional
handling is intended and already tested (test_optional_field, test_pipe_union_field).

Root cause & fix

agent/react/json_utils.py — inside _recursive_search, search every non-None union member
(recursively, including a union nested as a list's inner type) instead of collapsing to the first.
A new _union_members helper returns the non-None members of a union, or [annotation] for a
non-union — so non-union fields behave byte-identically to before. _unwrap_optional is left
unchanged; it still serves Optional-stripping in the RootModel root-peel and _coerce_field,
which only ever see single-member optionals.

This is a single change in the shared producer through which all callers route
(get_job_attachment_paths is the only production caller), not a per-caller patch.

Tests

Added TestGetJsonPathsByTypeUnions covering second-branch unions, optional unions, PEP-604
three-member unions, list[Union[...]], a union member that nests the type, multiple branches
referencing the type, the first-branch baseline, and the dynamic anyOf/$ref case. Each fails
on the current code and passes with the fix. Full tests/agent/react + tests/agent/tools suite:
893 passed.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud