docs: third-party RandomX miners cannot mine Bitflash pools

The README offered XMRig and SRBMiner command lines pointed at the local
Stratum bridge. Neither can work. In RandomX mode both target the
Monero-style JSON-RPC protocol (login/job/submit) while the pool speaks
Bitcoin-style Stratum (mining.subscribe/notify/submit); both place the
nonce at byte 39 of the job blob, which in an 80-byte Bitflash header is
inside the merkle root, not the nonce at byte 76; and both require a
32-byte seed hash as 64 hex characters, where randomx_pow.cpp keys RandomX
from a fixed 36-byte string that is not a hash at all. None of it is
configurable.

-stratumbridge is a byte relay between a local socket and the .btf tunnel
(BridgePump, main.cpp) -- it fixes reachability, the one blocker an
operator could otherwise do something about, and translates nothing. Say
that where the commands used to be, so the question gets answered instead
of asked again.

Also correct the magic bytes in src/readme.txt, which documented
bf 1a 5c fd; net.h has bf 20 5c fd.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/readme.txt b/src/readme.txt
index 752be66..7490a9a 100644
--- a/src/readme.txt
+++ b/src/readme.txt
@@ -16,7 +16,7 @@ This product includes software developed by the OpenSSL Project.
 Differences from the original Bitcoin
 -------------------------------------
 - Own genesis block (22/Jul/2026 headline, independent chain)
-- Own magic bytes (0xbf 0x1a 0x5c 0xfd) and P2P port 8433
+- Own magic bytes (0xbf 0x20 0x5c 0xfd) and P2P port 8433
 - Addresses start with "B" (ADDRESSVERSION = 25)
 - Consensus fixes applied: value overflow (CVE-2010-5139), duplicate inputs,
   money range checks (MoneyRange)