Fix/expected share reduction

[Priceless-P]

The expected hash rate is ~30% lower than the -d value due to aggressive difficulty rounding. This change:

• Adjusts the calculation so that the resulting initial hash rate better matches the miner's -d value.
  • Fixes Investigate why expected hashrate is almost 30% from specified in -d arg #93
• Fixes cargo fmt, clippy and test issues introduced by the previous pr merges

[jbesraa]

@Priceless-P I checked to the branch locally and tested and this is what Iam seeing

2025-06-25T10:41:53.447480Z  INFO demand_cli::translator::downstream::accept_connection: Translator opening connection for ip 10.100.102.32
2025-06-25T10:41:53.447485Z  INFO demand_cli::translator::downstream::accept_connection: Translator initial hash rate for ip 10.100.102.32 is 1000000000000 H/s
2025-06-25T10:41:53.447488Z  INFO demand_cli::translator::downstream::accept_connection: Translator share per second for ip 10.100.102.32 is 0.16666667 shares/s
2025-06-25T10:41:53.447501Z  INFO demand_cli::translator::downstream::accept_connection: Translator initial difficulty for ip 10.100.102.32 is 1000
2025-06-25T10:41:53.447505Z  INFO demand_cli::translator::downstream::accept_connection: Translator expected hash rate for ip 10.100.102.32 is 715827900000 H/s

[jbesraa]

this is the initial set_difficulty the miner get:

₿ (16403) stratum_task: rx: {"method":"mining.set_difficulty","params":[1000.0]}

this seems correct and identical to what is printed above

[Priceless-P]

@jbesraa , please confirm if you are the correct branch.
this is what I get from my end with downstream_hashrate = "0.00001T"

2025-06-25T10:52:24.504477Z  INFO demand_cli::translator::downstream::accept_connection: Translator initial hash rate for ip 127.0.0.1 is 10000000 H/s
2025-06-25T10:52:24.504501Z  INFO demand_cli::translator::downstream::accept_connection: Translator share per second for ip 127.0.0.1 is 0.16666667 shares/s
2025-06-25T10:52:24.504523Z  INFO demand_cli::translator::downstream::accept_connection: Translator initial difficulty for ip 127.0.0.1 is 0.02
2025-06-25T10:52:24.504544Z  INFO demand_cli::translator::downstream::accept_connection: Translator expected hash rate for ip 127.0.0.1 is 14316558 H/s

[jbesraa]

here are last commits on the branch iam on

97bd979 (HEAD, prisca/fix/expected-share-reduction) add docs and fix CI checks
727f3f1 update `nearest_power_of_10`

I tried it another couple of times:

2025-06-25T11:28:28.007022Z  INFO demand_cli::translator::downstream::accept_connection: Translator opening connection for ip 10.100.102.32
2025-06-25T11:28:28.007027Z  INFO demand_cli::translator::downstream::accept_connection: Translator initial hash rate for ip 10.100.102.32 is 1000000000000 H/s
2025-06-25T11:28:28.007031Z  INFO demand_cli::translator::downstream::accept_connection: Translator share per second for ip 10.100.102.32 is 0.16666667 shares/s
2025-06-25T11:28:28.007043Z  INFO demand_cli::translator::downstream::accept_connection: Translator initial difficulty for ip 10.100.102.32 is 1000
2025-06-25T11:28:28.007046Z  INFO demand_cli::translator::downstream::accept_connection: Translator expected hash rate for ip 10.100.102.32 is 715827900000 H/s
2025-06-25T11:28:28.007050Z DEBUG demand_cli::translator::downstream::accept_connection: Bridge is ready, proceeding with connection
2025-06-25T11:28:28.007057Z  INFO demand_cli::translator::proxy::bridge: New extended channel opened with id 1
2025-06-25T11:28:28.007064Z  INFO demand_cli::translator::downstream::accept_connection: Translator opening

Try to add more tests to cover different larger numbers