QuoteHub: Ignore Insert/Add operations for quotes preceding current timeline

[coderabbitai]

Problem

When QuoteHub has pruned historical quotes and the cache contains only the most recent N quotes, calling Insert(quote) or Add(quote) with a quote that precedes the current timeline (before the first timestamp in the cache) creates an indeterminate gap in the data.

Current Behavior

• After pruning, cache contains quotes [500..2000] (if max cache size is 1500)
• Calling Insert(quote_100) would:
  • Slot in at beginning of timeline
  • Create gap: quote 100, then missing 101-499, then 500-2000
  • Increase cache size without triggering prune
  • Send rebuild command to subscribers

Expected Behavior

QuoteHub should ignore Insert and Add operations for quotes that precede the current timeline (before Results[0].Timestamp after pruning).

Implementation Notes

• Check if incoming quote timestamp is before Results[0].Timestamp
• If yes, ignore the operation (no-op)
• Consider logging a debug message for such cases
• This prevents indeterminate gaps and maintains timeline integrity

Related

• PR: Fix SSE integration test comparison logic to use correct series pattern #1941
• Discussion: Fix SSE integration test comparison logic to use correct series pattern #1941 (comment)
• Assignee: @DaveSkender