optimizer combination limit doubled to 20 million

the algo optimizer now tests up to 20 million setting combinations in a single run, double the previous cap of 10 million. both engulfing algos now go up to 15 million combinations. each engulfing trade depends on where the previous one exited, so every combination takes more processing to test.

a higher cap lets wider parameter ranges and finer steps fit into one sweep. profit target, stop loss, entry level and entry cutoff ranges that used to hit the limit can now run without being narrowed first, so more of the setting space gets tested before the optimizer ranks the results.