docs(forms): use the when option in disabled examples

Passing a function or string directly to `disabled()` is deprecated in
favor of `{when: ...}`. The `SchemaFn` API example, the schemas guide
diagram and an internal comment still showed the deprecated form.

Built with `//adev:build`.

Author: MeAkib

adev/src/content/guide/forms/signals/schemas.md

@@ -19,7 +19,7 @@ contactForm = form(this.contactModel, (schemaPath) => {
 graph TD
     A["form(model, schemaFn)"] --> B["Schema function runs ONCE"]
     B --> C["required(path)"]
-    B --> D["disabled(path, logicFn)"]
+    B --> D["disabled(path, {when: logicFn})"]
     B --> E["validate(path, logicFn)"]
     B --> F["apply(path, schema)"]
     C --> G["Reactive: recomputes on signal change"]

packages/forms/signals/src/api/types.ts

@@ -835,7 +835,7 @@ export type Schema<in TModel> = {
  * ```typescript
  * const userFormSchema: SchemaFn<User> = (p) => {
  *   required(p.name);
- *   disabled(p.email, ({valueOf}) => valueOf(p.name) === '');
+ *   disabled(p.email, {when: ({valueOf}) => valueOf(p.name) === ''});
  * };
  *
  * const f = form(userModel, userFormSchema, {injector});

packages/forms/signals/src/field/resolution.ts

@@ -26,7 +26,7 @@ export function getBoundPathDepth() {
  *
  * ```ts
  * const s = schema(p => {
- *   disabled(p.next, ({valueOf}) => valueOf(p.data));
+ *   disabled(p.next, {when: ({valueOf}) => valueOf(p.data)});
  *   apply(p.next, s);
  * });
  * ```