HTTP timeouts (context deadline exceeded, Client.Timeout) were
incorrectly classified as context window errors, triggering useless
history compression. Replace broad substring checks ("context",
"token", "length") with specific patterns for real context limit
errors and explicitly exclude timeout errors from that path.
Additionally, timeout errors were not retried at all — the retry
loop only handled context window errors. Now timeouts are retried
up to 2 times with exponential backoff (5s, 10s).
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