Version history and AI search consistency

A consistency pass across version history, AI search, and pricing copy.

• Item version records now always capture the result of an edit — clearing up version lists that could show two identical-looking rows when edits came through an agent connection
• Renaming a category now flows into the AI search index on a regular sweep, fixing searches that only matched the old name
• Aligned the voice limits on the pricing page with actual processing — uploaded audio files run up to 90 minutes on Pro and 4 hours on Pro+ and up, as announced on August 13
• Leftover sync jobs on expired accounts are now cleaned up, along with some internal safeguard polish