fix: improve memory_search retry logic for Node 22

[tryweb]

Summary

Fix flaky test memory_delete and memory_clear reject destructive operations without confirmation on Node 22.

Problem

• Test consistently fails on Node 22 but passes on Node 20 and 24
• Search returns "No relevant memory found" immediately after capture
• Race condition: data not fully written before search executes

Solution

• Add 200ms initial delay after capture before first search
• Increase retry count from 3 to 5
• Increase delay between retries from 100ms to 150ms
• Simplify retryWithDelay to return last result instead of throwing error

Verification

• Local test passes with 555ms duration