fix(server): include daily_allocations in TaskFieldsBase server response model

[amir-rezaei]

Description

This PR resolves issue #1135 by adding daily_allocations: dict[str, float] to TaskFieldsBase in packages/taskdog-server/src/taskdog_server/api/models/responses.py.

Details

• Previously, TaskFieldsBase omitted daily_allocations, causing FastAPI response serialization of write operations (TaskOperationResponse, UpdateTaskResponse) to drop daily_allocations.
• As a result, the client always validated and deserialized daily_allocations to an empty dictionary {} after create, update, or lifecycle calls.
• Adding daily_allocations ensures full feature parity and complete data round-tripping between the server response models and client DTOs.

[Kohei-Wada]

Confirmed the underlying bug — TaskOperationOutput declares daily_allocations while TaskFieldsBase omits it, so the client validates it to {} on every write response. The fix is right.

Before merging, please add tests. This PR is a one-line field addition with no coverage, and #1135 explicitly asks for the drift guard rather than just the field:

1. A drift test so the two hand-maintained shapes cannot silently diverge again:

   assert set(TaskOperationResponse.model_fields) == set(TaskOperationOutput.model_fields)

2. A round-trip test: a create/update/lifecycle response carrying a non-empty daily_allocations should still be non-empty after the client deserializes it.

Verified locally against current main: lint, typecheck and the full suite pass (ruff is now 0.16, so please rebase).