docs: correct divergences found in full implementation audit

- Cargo.toml: bump rust-version 1.94 -> 1.96 to match rust-toolchain.toml
  pin and the "Rust 1.96+" claim in README/install docs.
- architecture.md: the generated php.* facade leaf is a plain function using
  Array.prototype.slice.call(arguments), not an arrow with rest params; name
  the re-entrancy depth cap (200).
- execution-modes.md: the isolated-realm stored-callback error is a plain
  \Exception (PhpException::default), not QuickJSException.
- docs/README.md: add the missing src/sandbox.rs row and roundtrip() to the
  lib.rs method list in the source map.
- api.md: document roundtrip() so the reference covers every public method.

Author: eddmann

Cargo.toml

@@ -2,7 +2,7 @@
 name = "php_quickjs"
 version = "0.0.2"
 edition = "2021"
-rust-version = "1.94"
+rust-version = "1.96"
 description = "Embed a QuickJS sandbox in PHP with typed, bidirectional communication"
 license = "MIT"
 authors = ["Edd Mann <the@eddmann.com>"]

docs/README.md

@@ -30,8 +30,9 @@ php -d extension=$(pwd)/target/debug/libphp_quickjs.so examples/kitchen_sink.php
 
 | File | Responsibility |
 |------|----------------|
-| `src/lib.rs` | The `QuickJS` PHP class: `eval` / `register` / `grant` / `resolve` / `revoke` / `manifest` / `dts`. |
+| `src/lib.rs` | The `QuickJS` PHP class: `eval` / `register` / `grant` / `resolve` / `revoke` / `manifest` / `dts` / `roundtrip`. |
 | `src/engine.rs` | Owns the QuickJS `Runtime`; realm lifecycle (shared vs isolated); deadline + re-entrancy state; the current-context stack. |
+| `src/sandbox.rs` | In-engine resource containment: the memory limit, native stack size, and wall-clock deadline (interrupt handler). |
 | `src/transpile.rs` | TypeScript → JavaScript via oxc, plus the content-hash transpile cache. |
 | `src/bridge.rs` | The `__host` / `__php_invoke` imports, the dispatch table, the frozen `php.*` facade, and registries. |
 | `src/marshal.rs` | `JS value ↔ MiddleValue ↔ PHP zval`, with native-msgpack (de)serialization. |

docs/api.md

@@ -37,3 +37,9 @@ $js->register('db.query', fn(int $handle, string $sql) => $js->resolve($handle)-
 
 The registration manifest and a generated TypeScript `.d.ts` for the `php` global,
 both from the same source of truth.
+
+### `roundtrip(mixed $value): mixed`
+
+Diagnostic helper: send a PHP value through the full marshaling pipeline
+(PHP → MiddleValue → JS → MiddleValue → PHP) and return the result. Useful for
+testing value fidelity across the boundary; not needed in normal use.

docs/architecture.md

@@ -29,10 +29,12 @@ Take `php.math.add(2, 3)` from a guest script.
 
 2. The guest calls `php.math.add(2, 3)`. `php` is not magic — it is a **frozen JS
    object tree** that `bridge.rs` generated from the registration manifest. The
-   leaf `php.math.add` is an arrow function:
+   leaf `php.math.add` is a function:
 
    ```js
-   php.math.add = (...args) => globalThis.__rt.callHost("math.add", args);
+   php.math.add = function () {
+     return globalThis.__rt.callHost("math.add", Array.prototype.slice.call(arguments));
+   };
    ```
 
 3. `__rt.callHost` (`src/js/runtime.js`) **msgpack-encodes** the argument array
@@ -56,7 +58,7 @@ surface.
 ### The facade is generated, and frozen
 
 `bridge.rs::build_facade` walks the manifest's dotted names into a nested object
-tree, makes each leaf an arrow calling `__rt.callHost("dotted.name", args)`, then
+tree, makes each leaf a function calling `__rt.callHost("dotted.name", args)`, then
 **deep-freezes** the whole tree. Freezing is a security requirement, not a
 nicety: a guest must not be able to reassign `php.http.get` to fool other code.
 The facade is (re)built at the start of every `eval` so newly registered
@@ -123,7 +125,7 @@ while a host call is already running* (e.g. `php.mapEach(xs, fn)` — PHP calls
 eval) is active, the live `Ctx` pointer is published on a thread-local
 **current-context stack** (`engine.rs`), and `Js\Callback` reuses it instead of
 re-locking. Only when invoked *between* evals (no realm active) does it acquire
-the lock fresh on the persistent realm. A re-entrancy **depth cap** bounds
+the lock fresh on the persistent realm. A re-entrancy **depth cap** (200) bounds
 runaway PHP→JS→PHP→… recursion.
 
 ## Capability handles

docs/execution-modes.md

@@ -75,7 +75,7 @@ error rather than misbehaving:
 $held = null;
 $js->register('keep', function ($cb) use (&$held) { $held = $cb; });
 $js->eval('php.keep(() => 1)');
-$held();   // QuickJSException: "JS callback invoked outside its eval (isolated …)"
+$held();   // Exception: "JS callback invoked outside its eval (isolated …)"
 ```
 
 ## Why exactly those differences (the mechanism)