Add delete confirmation for user-saved templates

[jerelvelarde]

Problem

Clicking the Delete button on a user-saved template in the template library drawer permanently removes it with no confirmation. A single misclick causes irreversible data loss.

Suggested fix

Add one of:

• An undo toast that appears for a few seconds after deletion, allowing the user to restore
• A brief confirmation dialog before deleting
• A soft-delete with a "Recently Deleted" section

An undo toast is probably the lightest-weight option that still provides a safety net.

Files

• apps/app/src/components/template-library/index.tsx
• apps/app/src/components/template-library/template-card.tsx

From PR #20 review