fix/correctness-silent-drops: close nine tier-1 silent-drop bugs on the path to v2.0

[vedanthvdev]

Why

A second, deeper multi-agent review of the plugin source tree as it landed in v1.9.19 surfaced a cluster of tier-1 correctness bugs that all shared the same failure mode: a strategy thought it had walked a construct but had actually missed one of its real-world shapes, so the consumer test for a changed class never entered the selected set. This breaks the plugin's cardinal invariant — run more tests than needed, never fewer — which is the one guarantee v2.0 needs to ship with.

Every fix in this PR ships with at least one regression test that fails when the production fix is reverted.

What

New file: affected-tests-core/src/main/java/io/affectedtests/core/discovery/JavaParsers.java

#	Fix	Regression test
1	JavaParsers factory centralises JavaParser creation at LanguageLevel.JAVA_25 (highest stable level the bundled 3.28 build supports). new JavaParser() defaulted to JAVA_11, so every file using records, sealed types, or pattern matching parsed as isSuccessful == false and silently dropped out of every AST strategy. parseOrWarn now centralises the parse helper and surfaces failures at WARN instead of DEBUG.	ImplementationStrategyTest#findsRecordImplementationOfChangedInterface, …findsEnumImplementationOfChangedInterface
2	TransitiveStrategy preserves generic arguments (List<Foo> now registers the Foo edge) by walking every ClassOrInterfaceType.	TransitiveStrategyTest#preservesGenericArgumentsInReverseDependencyEdges
3	TransitiveStrategy scans method bodies, not just signatures, so new PricingCalculator() inside a method body now adds the reverse edge.	TransitiveStrategyTest#discoversEdgesFromMethodBodyReferences
4	ImplementationStrategy iterates every TypeDeclaration subtype. Records and enums are now first-class implementers; a defensive WARN-logged default branch guards against the same bug reappearing when JavaParser introduces a new declaration kind.	(same two tests as #1)
5	GitChangeDetector now diffs against the merge-base between baseRef and HEAD via RevFilter.MERGE_BASE, falling back to baseId with a WARN log when there is no common ancestor. Previously, any post-divergence master commit showed up as a "change" on the feature branch and dragged unrelated tests into every MR.	GitChangeDetectorTest#diffsAgainstMergeBaseNotBaseRefTip
6	UsageStrategy adds a Tier 3 AST pass that catches fully-qualified inline references (new com.example.Foo(), Outer.Inner inline qualification).	UsageStrategyTest#findsTestThatUsesChangedClassByFullyQualifiedInlineReference, …findsTestThatInnerClassQualifiesThroughChangedOuter
7	UsageStrategy Tier 1b now treats import pkg.Outer.* as a class-member wildcard (dependency on pkg.Outer) rather than a package wildcard.	UsageStrategyTest#findsTestThatWildcardsClassMembersOfChangedClass
8	PathToClassMapper routes module-info.java and package-info.java to the unmapped bucket instead of minting the malformed FQNs module-info / com.example.package-info.	PathToClassMapperTest#moduleInfoRoutesToUnmappedNotProduction, …packageInfoRoutesToUnmappedNotProduction
9	AffectedTestsEngine explicitly routes diffs that are a union of ignored + out-of-scope files to Situation.ALL_FILES_OUT_OF_SCOPE (SKIPPED) instead of falling through to DISCOVERY_EMPTY — which under mode = CI would escalate a pure docs+api-test MR into a full CI run.	AffectedTestsEngineTest#mixedIgnoredAndOutOfScopeDiffRoutesToAllFilesOutOfScope

Verification

• ./gradlew check — green end-to-end (core + gradle modules, validatePlugins included).
• New regression tests: 11 new tests, all passing. Each one reverse-checks its fix: mutating the production code in-place makes the test fail.
• Independent code-reviewer pass on the staged diff surfaced 1 High (LANGUAGE_LEVEL = JAVA_21 → bump to JAVA_25) and 3 Medium findings (parse-failure WARN, supertypesOf default branch, merge-base fallback log level). All four applied in this PR. Zero Critical findings remaining.

Release

This is batch 4 of 4 on the road to v2.0. Ships as v1.9.20 via the axion-release workflow on merge to master.

See the CHANGELOG.md top block "Fixed — post-v1.9.19 multi-reviewer correctness pass (v1.9.20)" for the authoritative per-fix writeup.