Rename the `SymbolTable symbols` field in `VM` struct to `methods` to clarify its purpose for method dispatch, and update all references across `vm.c`, `vm.h`, `primitives.c`, and `compiler.c`. Rename `defineName` to `declareVariable` to better reflect its actual behavior of declaring a variable without defining it. Remove the unused `internSymbol` helper function. Add `clearSymbolTable(&vm->globalSymbols)` to `freeVM` to fix a memory leak. Update `dumpCode` signature to take `VM*` and `ObjFn*` instead of `ObjBlock*`, and display method names via `getSymbolName`. Add `stackStart` field to `CallFrame` replacing `locals` for clearer semantics. Introduce `test/method_arity.wren` to validate method dispatch with up to 10 parameters.
