fix : added console.error for silent localStorage catch in useMixedTasks

[tmdeveloper007]

Summary of What Has Been Done

Replaced the silent catch block comment // ignore localStorage failures with console.error(...) in the useMixedTasks.js hook to provide visibility when localStorage persistence fails.

Changes Made

1. frontend/src/hooks/useMixedTasks.js line 65: Changed // ignore localStorage failures to console.error("Failed to persist routine tasks to localStorage:", error);.

Impact it Made

• Developers can diagnose localStorage quota exceeded or private browsing mode issues.
• Aligns with the existing console.error pattern already used in the same file for the CustomEvent dispatch error path.
• Maintains the same non-blocking behavior (the error is logged but does not throw), while providing visibility.

Closes #2034

Note: Please assign this PR to the tmdeveloper007 account.