fix(kotlin): resolve chained companion-factory calls Foo.getInstance().bar() (#750) (#752)

A Kotlin method called through a companion-object factory, fluent chain, or
constructor — `Foo.getInstance().bar()`, `Config.create(opts).build()`,
`STMTransaction(f).commit()` — dropped the receiver to a BARE method name, which
then name-matched a same-named method on an unrelated class (a wrong edge) or
failed to resolve. Ports the #645/#608 mechanism to Kotlin:

- Part 1: capture Kotlin return types in the extractor. tree-sitter-kotlin
  exposes no field names, so the return type is read positionally (the type node
  after function_value_parameters); inferred/Unit/Nothing returns yield none.
- Part 2: encode a CLASS/companion-factory call-receiver chain as `inner().method`.
  Gated to a capitalized receiver (`Foo.getInstance()` / `Foo(args)`) so instance
  chains (`list.filter{}.map{}`) keep their bare-name behavior — re-encoding those
  would only drop the edge, regressing recall in fluent codebases.
- Part 3: generalize matchJavaCallChain -> matchDottedCallChain (shared by the JVM
  dot-notation languages); resolve the method on the factory's return type, or on
  the constructed class for a Kotlin `Foo(args).method()` receiver. Validated via
  resolveMethodOnType, so a wrong inference yields NO edge.

Validated: synthetic decoy + args + absent-method safety tests; full suite green;
real-repo A/B on arrow-kt/arrow (734 .kt) — node count identical (no explosion),
+49 validated-correct chained edges, and the removed edges are wrong bare-name
guesses the fix correctly stops emitting (419/438 from test/doc files; the 18
from product code are stdlib `.apply{}`, self-loops, and bare-name mismatches) —
a net precision improvement, ~0 correct product edges lost. Java path unchanged
(constructor branch is Kotlin-gated). EXTRACTION_VERSION 6 -> 7.

Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/extraction/extraction-version.ts

@@ -21,4 +21,4 @@
  * turns the re-index hint into noise — keep it honest (see CLAUDE.md, "Honesty
  * in the product is load-bearing").
  */
-export const EXTRACTION_VERSION = 6;
+export const EXTRACTION_VERSION = 7;