fix(contracts): advertise NUL with a portable hex escape

Use the equivalent hex NUL spelling in named public contracts while preserving current path and reserved-name validation. Verify converted JSON Schema and real stdio catalog consumers.

Closes #1329

Co-authored-by: Yi-111-a <97448247+Yi-111-a@users.noreply.github.com>

src/contracts/native/nativeToolContracts.ts

@@ -71,7 +71,7 @@ export const swiftSymbolsSchema = z
       .string()
       .min(1)
       .regex(/^[^\n]*$/u, "Each Swift symbol must be one line.")
-      .regex(/^[^\u0000]*$/u, "Swift symbols cannot contain NUL."),
+      .regex(/^[^\x00]*$/u, "Swift symbols cannot contain NUL."),
   )
   .min(1);
 

src/domain/apple/dylibResolution.ts

@@ -25,7 +25,7 @@ import {
  * patterns avoid look-around, which RE2 and Rust validators reject.
  */
 const ROOT_RELATIVE_PATH =
-  /^(?:[^\x2f\\\u0000.][^\x2f\\\u0000]*|\.[^\x2f\\\u0000.][^\x2f\\\u0000]*|\.\.[^\x2f\\\u0000]+)(?:\x2f(?:[^\x2f\\\u0000.][^\x2f\\\u0000]*|\.[^\x2f\\\u0000.][^\x2f\\\u0000]*|\.\.[^\x2f\\\u0000]+))*$/u;
+  /^(?:[^\x2f\\\x00.][^\x2f\\\x00]*|\.[^\x2f\\\x00.][^\x2f\\\x00]*|\.\.[^\x2f\\\x00]+)(?:\x2f(?:[^\x2f\\\x00.][^\x2f\\\x00]*|\.[^\x2f\\\x00.][^\x2f\\\x00]*|\.\.[^\x2f\\\x00]+))*$/u;
 const rootRelativePathSchema = z
   .string()
   .min(1)

src/domain/javascript/electronActiveObservation.ts

@@ -81,7 +81,7 @@ export const electronActiveObservationInputSchema = z.strictObject({
     .array(
       z
         .string()
-        .regex(/^[^\u0000]*$/u, "Electron arguments must not contain NUL"),
+        .regex(/^[^\x00]*$/u, "Electron arguments must not contain NUL"),
     )
     .default([]),
   actions: z.array(actionSchema).default([]),

src/domain/localPath.ts

@@ -1,11 +1,19 @@
 import { isAbsolute, relative, sep } from "node:path";
 import { z } from "zod";
 
-/** Preserve selected filesystem names while rejecting OS-invalid NUL bytes. */
+/**
+ * Preserve selected filesystem names while rejecting OS-invalid NUL bytes.
+ *
+ * The pattern spells NUL as `\x00` rather than `\u0000`. Both accept exactly the
+ * same strings. The hex form also avoids the short `\0` spelling rejected by
+ * strict schema consumers. A client can reject its entire tool request when
+ * one advertised pattern cannot compile. See `offsetDateTimeSchema` for the
+ * same hex-escape convention.
+ */
 export const localPathStringSchema = z
   .string()
   .min(1)
-  .regex(/^[^\u0000]*$/u, "Local filesystem paths cannot contain NUL");
+  .regex(/^[^\x00]*$/u, "Local filesystem paths cannot contain NUL");
 
 /** Test lexical containment on the host platform; callers must resolve symlinks first. */
 export const isPathWithinRoot = (root: string, path: string): boolean => {

src/domain/native/nativeCallObservation.ts

@@ -5,7 +5,7 @@ const hexSchema = z.string().regex(/^0x[0-9a-f]+$/u);
 const nativeString = z
   .string()
   .regex(
-    /^[^\u0000]*$/u,
+    /^[^\x00]*$/u,
     "Native launch and breakpoint strings cannot contain NUL",
   );
 /** Objective-C class names and selectors never contain spaces or brackets. */
@@ -61,10 +61,8 @@ export const nativeCallObservationInputSchema = z.strictObject({
       z
         .string()
         .min(1)
-        .regex(/^[^=\u0000]+$/u, "Environment names cannot contain '=' or NUL"),
-      z
-        .string()
-        .regex(/^[^\u0000]*$/u, "Environment values cannot contain NUL"),
+        .regex(/^[^=\x00]+$/u, "Environment names cannot contain '=' or NUL"),
+      z.string().regex(/^[^\x00]*$/u, "Environment values cannot contain NUL"),
     )
     .default({})
     .describe("Overrides on top of the environment REA runs with."),

src/domain/process/processScenario.ts

@@ -5,7 +5,7 @@ import { z } from "zod";
 const positiveBudget = z.number().int().safe().positive();
 const timedEventBase = { at_ms: z.number().int().safe().nonnegative() };
 const reservedRunIdEnvironmentName = "REA_PROCESS_RUN_ID";
-const ENVIRONMENT_NAME_CHARACTER = "[^=\\u0000]";
+const ENVIRONMENT_NAME_CHARACTER = "[^=\\x00]";
 
 /**
  * Nonempty environment names other than the reserved run identifier. The
@@ -20,7 +20,7 @@ const environmentNamePattern = (reserved: string): RegExp => {
     const character = reserved[index] ?? "";
     // Diverge here, match the next reserved character, or (after a nonempty
     // prefix) end the name early.
-    const choice = `[^=\\u0000${character}]${ENVIRONMENT_NAME_CHARACTER}*|${character}${rest}`;
+    const choice = `[^=\\x00${character}]${ENVIRONMENT_NAME_CHARACTER}*|${character}${rest}`;
     rest = index === 0 ? choice : `(?:${choice})?`;
   }
   return new RegExp(`^(?:${rest})$`, "u");
@@ -38,7 +38,7 @@ const environmentName = z
 const childProcessString = z
   .string()
   .regex(
-    /^[^\u0000]*$/u,
+    /^[^\x00]*$/u,
     "Values passed to operating-system APIs cannot contain NUL",
   );
 export const normalizationSchema = z.object({

tests/boundary/mcp/advertisedPatternsVMode.test.ts

@@ -79,9 +79,12 @@ it("advertises portable NUL escapes and patterns that compile in all JS modes",
   ).toEqual([]);
 
   // DeepSeek rejects the short NUL escape even though V8 accepts it in all
-  // three modes. Schema compilation must not hide that interchange failure.
-  expect(patterns.filter(({ pattern }) => pattern.includes("\\0"))).toEqual([]);
-  expect(patterns.some(({ pattern }) => pattern.includes("\\u0000"))).toBe(
-    true,
-  );
+  // three modes. Keep the shared hex spelling across the advertised catalog;
+  // actual provider acceptance is verified separately from JS compilation.
+  expect(
+    patterns.filter(
+      ({ pattern }) => pattern.includes("\\0") || pattern.includes("\\u0000"),
+    ),
+  ).toEqual([]);
+  expect(patterns.some(({ pattern }) => pattern.includes("\\x00"))).toBe(true);
 });