Talia sourcing improvements and email normalization

Improved

• Talia's sourcing commands are more reliable Talia now asks for confirmation before running a search or re-scoring applicants, and no longer gets stuck or silently substitutes prospects when you ask about a specific role. Sourcing, screening, and outreach commands all behave more predictably.
• Email addresses are saved in lowercase When you add a new user, their email is automatically lowercased and trimmed as you type — so you don't have to worry about capitalization. A short note under the field confirms what will be saved.