BIP9Stats.possible uses a strict > so a period that can still exactly reach threshold is reported impossible

This description is AI generated, mistakes can be made.

Intent: Break the documented meaning of BIP9Stats::possible ('False if there are not enough blocks left in this period to pass activation threshold') at its boundary: the case where every single remaining block must signal is still possible, but is now reported as hopeless.

Behaviour change: With period 2016 / threshold 1916, after exactly 100 non-signalling blocks the original still reports possible=true (the fork activates if every remaining block signals); the mutant reports possible=false and getdeploymentinfo then omits both 'threshold' and 'possible' from the statistics object only when threshold is also 0 - in the STARTED case it reports "possible": false while activation is still achievable.

Trigger: getdeploymentinfo (or the REST /deploymentinfo endpoint) on any node whose current period has exactly period-threshold non-signalling blocks so far - e.g. regtest testdummy with 36 of the first 36 blocks of a 144-block period not signalling, then querying at any point before the period ends.

Spec violation: versionbits.h: '/** False if there are not enough blocks left in this period to pass activation threshold */ bool possible' - with elapsed-count == period-threshold there are exactly enough blocks left.

Severity if undetected: low

Why tests miss it: grepped 'possible' across test/functional (only rpc_blockchain.py, where count == elapsed so both sides are true) and src/test (only the fuzz target); GetStateStatisticsFor is never called from versionbits_tests.cpp

Plausibility: The expression is already written in a slightly awkward 'slack >= deficit' form; flipping it to a strict inequality is the classic off-by-one a reader cannot check without re-deriving the algebra, and no reviewer sees a failing test.

Equivalence risk: Only differs on the exact boundary (elapsed-count == period-threshold); every test period so far has elapsed == count, where both forms are true.