Accounts: Warn on duplicate name or address when creating an account

Sales teams growing past a few thousand active accounts routinely create duplicates because there's no inline warning at creation time. Today the platform exact-matches on submit and surfaces a post-submit dialog, plus an as-you-type substring suggestion list — but neither catches address-based duplicates.

What would help

• Pre-submit inline panel showing possible duplicates (name and/or address match)
• Trigger on address autocomplete selection too — if the address already exists on another account, surface immediately
• Allow "create anyway" override with explicit confirmation, so users aren't blocked on legitimate edge cases (e.g., a second business at the same address)

This is mainly a data-quality issue at scale: duplicate accounts split project history, billing, and service records, which costs time to reconcile later.