Migrate off the retired tool-base artifact

[alexander-yevsyukov]

Migrates ProtoTap off the retired io.spine.tools:tool-base artifact onto the
focused modules that replaced it.

tool-base#189 split the
monolithic tool-base module into fs, code, archive, kotlin-code,
java-code, proto-code, and classic-codegen, and retired the
io.spine.tools:tool-base artifact. ProtoTap used exactly one symbol from it.

Imports migrated

From	To	File
io.spine.tools.code.proto.CodeGeneratorRequestWriter	io.spine.tools.proto.code.CodeGeneratorRequestWriter	protoc-plugin/src/main/kotlin/io/spine/tools/prototap/protoc/Plugin.kt

A repository-wide sweep for the other breaking changes in the split
(io.spine.tools.OsFamily, io.spine.tools.{div, resolve, toAbsoluteFile, isProtoSource}, io.spine.tools.StandardTypes, io.spine.tools.type,
Method(MethodSpec), io.spine.tools.java.code.{classSpec, constructorSpec, methodSpec, codeBlock}, Generated.dir / SourceRoot.subDir) found no other
occurrences — ProtoTap does not use any of them.

Dependency constants swapped

• protoc-plugin/build.gradle.kts — implementation(ToolBase.lib) →
  implementation(ToolBase.protoCode).
• buildSrc/src/main/kotlin/module.gradle.kts
  • force(...) list: ToolBase.lib → ToolBase.code, ToolBase.fs,
    ToolBase.protoCode.
  • Dropped substitute(module("io.spine.tools:spine-tool-base")).using(module(ToolBase.lib)).
    The legacy 1.x coordinate has no successor now that the monolith is gone, and
    substituting it onto an artifact that is never published would turn a dormant
    rule into a hard resolution failure. Verified that nothing pulls tool-base
    or spine-tool-base transitively: :protoc-plugin, :gradle-plugin, and
    :api runtimeClasspath are all clean.

grep -rn "ToolBase\.lib\|io\.spine\.tools:tool-base\|spine-tool-base" over the
repository now matches only the explanatory comment in module.gradle.kts.

ToolBase pinned to 2.0.0-SNAPSHOT.421

./config/pull ships ToolBase.version = "2.0.0-SNAPSHOT.420". This branch
deliberately moves it forward to 2.0.0-SNAPSHOT.421 in
buildSrc/src/main/kotlin/io/spine/dependency/local/ToolBase.kt, so the repo's
copy intentionally diverges from config until config catches up. All twelve
tool-base modules used here resolve at .421 from the Artifact Registry.

No dependency version moved backwards as a result of the config float — every
changed constant under buildSrc/src/main/kotlin/io/spine/dependency/ advanced.

Verification

• ./gradlew clean then ./gradlew build — SUCCESS (6 tests, 6 passed).
• ./gradlew dokkaGenerate — SUCCESS.
• docs/dependencies/pom.xml now records io.spine.tools:proto-code:2.0.0-SNAPSHOT.421
  and no longer mentions tool-base.
• Version bumped 0.16.0 → 0.17.0, migrating by extra(...) to extra.set(...).
• Reviewers: spine-code-review, kotlin-engineer, review-docs — all APPROVE.
  dependency-audit confirmed no version rollback; its remaining findings concern
  config-distributed files (Validation.kt, Compiler.kt, JacksonV2.kt) that
  are out of scope for a consumer repo per AGENTS.md § Code review.

Part of the Tier 1 tool-base split migration.

🤖 Generated with Claude Code

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 14.40%. Comparing base (43ac1ac) to head (ebd6124).

Additional details and impacted files

@@            Coverage Diff            @@
##             master      #20   +/-   ##
=========================================
  Coverage     14.40%   14.40%           
  Complexity        9        9           
=========================================
  Files             5        5           
  Lines           118      118           
  Branches          6        6           
=========================================
  Hits             17       17           
  Misses          101      101           

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