Function validateParsed

Walk a ParsedCsv once and emit a flat list of validation flags for the Import preview's checklist panel.

Flags emitted (always; level varies):

• row-count — error when zero rows, info otherwise (with the count).
• gps — info when any row carries lat + lon, warn when none do (the Map / MiniMap fall back to placeholders).
• monotonic — info when timestamps strictly ascend, warn when any pair is out of order.
• hybrid — info when any hybrid-specific PID appears.