fix(web-studio): respect task list query limit

[lk9100]

Description

Fix the Web Studio task page returning an empty list when connected to a server that enforces the task endpoint maximum of 200 results. The page requested limit=300 for the default scope and limit=10000 for the all-task scope, which caused HTTP 400 validation errors.

Human Involvement

• A human participated in the implementation or review loop
• This PR was generated entirely by AI agents without human participation in the loop

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change or refactoring

Changes Made

• Centralize the task query limit at the server-supported value of 200.
• Use the same safe limit for both recent and all-task scopes.
• Add regression tests for both query paths.

Testing

• Added tests proving both task scopes use limit=200.
• Web Studio test suite: 47 files, 180 tests passed.
• Web Studio production build passed on macOS.
• New helper and test pass lint and format checks.

The repository-wide lint/format commands still report pre-existing issues in unrelated task-page and monitoring files; this PR introduces no new lint errors.