fix(plugins): revert zksnark/commons-io alignment, document why

CI on rockylinux (x86_64 + JDK 8) failed under 0aebaff:

  org.tron.plugins.rocksdb.DbLiteRocksDbTest > testToolsWithRocksDB FAILED
    org.springframework.beans.factory.BeanCreationException: Error creating
    bean with name 'zksnarkInitService' ... NoClassDefFoundError:
    org/apache/commons/io/FileUtils

After commit 69d7f21 mirrored the :platform excludes onto :crypto
(reviewer's option A in #6738), x86 testRuntimeClasspath lost
commons-io:commons-io and io.github.tronprotocol:zksnark-java-sdk
entirely: both arrived only via :crypto -> :common -> :platform, which
is now also excluding them. ARM64 was unaffected because the ARM64
branch declares :platform without exclusions.

Diagnosis: the DbLiteTest Spring boot path loads
org.tron.core.zen.ZksnarkInitService, which references both
org.apache.commons.io.FileUtils and
org.tron.common.zksnark.LibrustzcashWrapper at runtime. Reproduced on
x86_64 docker:

  - removing only commons-io exclude -> FAILED at LibrustzcashWrapper
  - removing both exclusions          -> testToolsWithRocksDB PASSED

The :platform-side excludes for these two artifacts are therefore
deduplication only, not a "kept out of plugins" intent. The
leveldbjni-all exclude is the only one that must be mirrored, because
that one is the actual classpath conflict.

This commit drops the zksnark-java-sdk and commons-io excludes from
:crypto and adds a comment recording why they are intentionally
asymmetric with :platform.

Verified on x86_64 + JDK 8 (eclipse-temurin:8-jdk):
- :plugins:test passes (was 4 failed under 0aebaff)
- runtimeClasspath still does NOT contain leveldbjni-all 1.8
- runtimeClasspath now contains commons-io and zksnark-java-sdk
- Toolkit.jar smoke (db archive -d <empty>) still exits 0

Author: Barbatos

plugins/build.gradle

@@ -39,17 +39,20 @@ dependencies {
         exclude group: 'io.prometheus'
         exclude group: 'org.aspectj'
         exclude group: 'org.apache.httpcomponents'
-        // :crypto -> :common -> :platform transitively pulls in artifacts that
-        // the direct :platform dependency below already excludes on x86. Mirror
-        // those excludes here so both paths to :platform agree, otherwise the
-        // transitive copies leak into the fat jar. In particular leveldbjni-all
-        // 1.8 conflicts with io.github.tronprotocol leveldbjni-all 1.18.2: both
-        // jars carry org/iq80/leveldb/Options.class; the duplicate-entry write
-        // order in the fat jar can leave the 1.8 copy, which lacks
+        // :crypto -> :common -> :platform transitively pulls leveldbjni-all
+        // 1.8, which conflicts with the io.github.tronprotocol fork
+        // leveldbjni-all 1.18.2 declared below on x86. Both jars carry
+        // org/iq80/leveldb/Options.class; the duplicate-entry write order in
+        // the fat jar can leave the 1.8 copy, which lacks
         // Options.maxBatchSize(int) and breaks `db archive` at runtime.
+        //
+        // The direct :platform dependency below also excludes
+        // zksnark-java-sdk and commons-io, but those are *not* mirrored here:
+        // the plugins test runtime (DbLiteTest -> Spring -> ZksnarkInitService)
+        // actually loads classes from both, so :crypto must keep transitively
+        // providing them. The :platform-side excludes are deduplication, not
+        // a "kept out of plugins" intent.
         exclude group: 'org.fusesource.leveldbjni', module: 'leveldbjni-all'
-        exclude group: 'io.github.tronprotocol', module: 'zksnark-java-sdk'
-        exclude group: 'commons-io', module: 'commons-io'
     }
     implementation group: 'info.picocli', name: 'picocli', version: '4.6.3'
     implementation group: 'com.typesafe', name: 'config', version: '1.3.2'