feat(parsers): add Kotlin language support

[tob-scott-a]

Handles .kt and .kts files using tree-sitter-language-pack's kotlin grammar (transitive dep, no new installs). Extracts:

• Top-level functions (fun main, suspend fun fetch, ...)
• Classes, interfaces, data classes, objects, enum classes
• Methods inside class_body and enum_class_body
• Parameters from function_value_parameters and their user_type / type_identifier / nullable_type annotations
• Return types from the type node following : on the signature
• Imports — captured as graph.dependencies

Entrypoint detectors for Kotlin:

• Spring MVC / WebFlux annotations (@GetMapping, @PostMapping, etc.) reusing the existing Java detector since the annotations are identical across the two languages.
• Android component lifecycle methods: onCreate, onStart, onResume, onNewIntent, onActivityResult, onReceive, onBind, onHandleIntent. These are attacker-reachable when the component is exported — we over-detect on purpose and rely on the override file to tighten.

Known gap (parallel to Swift, documented in parser docstring): throw statements share their AST node type with return/break/continue via jump_expression, so exception-type capture needs a Kotlin-specific walk filtered by the leading throw token. Deferred.

14 new tests: Kotlin parser, Kotlin entrypoint detection. README supported-languages and framework-coverage tables updated.

Roadmap left before v0.2.0: Dart/Flutter parser, Go/Ruby/C++ entrypoint detectors (Option A), branches + docstring in JSON export (Option B).