Make bridge generation cacheable and incremental

[kdroidFilter]

Summary

• generateKneNativeBridges is now a @CacheableTask; sources are merged in a deterministic order (roots in declaration order, files sorted by relative path) so outputs are reproducible and relocatable.
• Source file → IR mapping: each file maps to a cached prescan + IR fragment (build/kne/incremental, Gradle local state). A file is re-parsed only if its content changed or a symbol it looked up now resolves differently. The PSI environment is not started when nothing needs parsing.
• IR → outputs mapping: codegen is skipped when the merged API is unchanged; otherwise only changed generated files are rewritten and stale ones deleted (previously the output dirs were wiped every run and stale jvmResources metadata was never cleaned).
• Type resolution moved to a PSI-free SymbolTable/TypeResolver with lookup tracking; KneType singletons are data objects with readResolve so they round-trip through the cache.
• Removed unused prescan sets; README updated.

Note: calculator's kne_bridges.kt / GraalVM JSON are reordered once due to the deterministic merge order (same content); systeminfo and benchmark outputs are byte-identical.

Test plan

• Plugin unit tests (new PsiSourceParserIncrementalTest, GeneratedOutputsTest)
• :examples:calculator:jvmTest and :examples:systeminfo:jvmTest pass; benchmark compiles
• Calculator: no change → UP-TO-DATE; body edit → 1 file parsed, codegen skipped; API edit → 1 file parsed, 2 outputs rewritten; revert → matches baseline
• Deleting outputs with --build-cache restores them FROM-CACHE