Drop altcoin pip extras, CI deps and docs; update CLAUDE.md and FORK.md

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.github/pull_request_template.md

@@ -1,4 +1 @@
-<!-- Note: Our primary focus is supporting Bitcoin, and contributions in that regard are appreciated the most!
-Due to historical reasons, ElectrumX also has support for many altcoins. These will be kept as long as
-maintenance burden can be kept *at a minimum*. When adding a new altcoin, (1) add a unit test (see tests/blocks),
-and (2) make sure the CI tests pass. -->
+<!-- Note: this fork supports Palladium (PLM) only. Add a unit test for new behavior and make sure the CI tests pass. -->

.github/workflows/ci.yml

@@ -46,18 +46,6 @@ jobs:
           # e-x itself
           # - install both leveldb and rocksdb bindings
           pip install ".[leveldb,rocksdb]"
-          # hashes and other altcoin-specific stuff
-          pip install tribushashm
-          pip install blake256
-          pip install dash_hash
-          pip install git+https://github.com/bitcoinplusorg/x13-hash
-          pip install xevan_hash
-          pip install quark_hash
-          pip install groestlcoin_hash
-          pip install x16r_hash
-          pip install pycryptodomex
-          pip install git+https://github.com/Electra-project/nist5_hash
-          pip install x16rv2_hash
 
       - name: Run pytest
         run: pytest --cov=electrumx