Pass through arbitrary Expr nodes in TypeWriter, add castInt() helper

[edalzell]

Problem

TypeWriter::write() only passes FuncCall instances through untouched. Any other hand-built AST node — say a Cast\Int_ for a literal (int) cast — falls through to TypeAnalyzer::typeOf(), which only understands scalars/arrays/null/bool/Closure and throws:

Exception: Support type: object

the moment that node ends up nested inside an array (which is effectively everywhere, since ArrayWriter recurses through TypeWriter::write() for every item). So there was no way to write something like (int) env('LIMIT', 20) as a config value — only the function-call form, intval(env('LIMIT', 20)), worked, even though the two aren't the same syntax you actually want when replicating an existing config file's style.

Solution

FuncCall already extends PhpParser\Node\Expr, so broadening the passthrough check from instanceof FuncCall to instanceof Expr is a strict generalization — everything that worked before still works, and any other expression node (casts, ternaries, etc.) can now be used as a config value too.

Added FunctionWriter::castInt(Expr $expr): Cast\Int_ as a small fluent helper on top of that, matching the style of the existing env()/basePath()/etc. helpers:

ConfigWriter::f()->castInt(ConfigWriter::f()->env('LIMIT', 20));
// => (int) env('LIMIT', 20)

Testing

New case in LaravelFunctionCallTest asserting castInt(env(...)) renders as (int) env(...). Same 2 pre-existing, unrelated failures as before (closure param formatting); nothing else regressed.

Note: branches off master, independent of #41 (this PR doesn't depend on it, and vice versa) — I merged both locally into a scratch branch to confirm they work together, which they do.