WIP: bump ember-source to 7.0.0-beta.1 + strip on/fn imports

Per review request: bump peer + dev to ^7.0.0-beta.1, downgrade
babel-plugin-ember-template-compilation to ^3.1.0 (matching the
7-beta @ember/app-blueprint), and remove all `import { on } from
'@ember/modifier'` / `import { fn } from '@ember/helper'` across
src/tests/demo/README/docs.

Currently broken: ember-source 7-beta's template compiler still runs
StrictModeValidationPass which rejects unbound `on`/`fn`. Both wire-format
(dev) and hbs-format (publish) paths hit this. ALLOWED_GLOBALS,
STRICT_MODE_KEYWORDS, and the eval()-form `inScope` check don't add
`on`/`fn` to the implicit scope. Needs guidance on the missing mechanism.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: NullVoxPopuli

docs/framework/ember/guides/arrays.md

@@ -33,8 +33,6 @@ export default class PeopleForm extends Component {
 This will regenerate the list every time you run `pushValue` on `field`:
 
 ```gjs
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 
 const addPerson = (field) => field.pushValue({ name: '', age: 0 });
 
@@ -47,8 +45,6 @@ const addPerson = (field) => field.pushValue({ name: '', age: 0 });
 Finally, you can use a subfield like so:
 
 ```gjs
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);
 const nameAt = (i) => `people[${i}].name`;
@@ -66,8 +62,6 @@ const nameAt = (i) => `people[${i}].name`;
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 import { createForm } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);

docs/framework/ember/guides/async-initial-values.md

@@ -25,8 +25,6 @@ Because `createForm` runs at component construction time, the simplest pattern i
 ```gjs
 // person-form.gts
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 import { createForm } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);

docs/framework/ember/guides/basic-concepts.md

@@ -69,8 +69,6 @@ Example:
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 import { createForm } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);
@@ -171,8 +169,7 @@ Example:
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { createForm } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);
@@ -230,8 +227,7 @@ Supported libraries include:
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { z } from 'zod';
 import { createForm } from '@tanstack/ember-form';
 
@@ -322,8 +318,6 @@ Example:
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 import { createForm } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);

docs/framework/ember/guides/dynamic-validation.md

@@ -144,8 +144,7 @@ You can also use `onDynamic` validation with fields, just like you would with ot
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { createForm, revalidateLogic } from '@tanstack/ember-form';
 
 const handleNumberInput = (field, event) =>

docs/framework/ember/guides/form-composition.md

@@ -51,8 +51,6 @@ The simplest way to remove boilerplate is to write small wrapper components that
 ```gjs
 // text-field.gts
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 
 const handleInput = (field, event) =>
   field.handleChange(event.target.value);
@@ -347,8 +345,6 @@ Now that we've covered the basics of composing forms, let's put it all together
 ```gjs
 // /src/components/text-field.gts
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);
 

docs/framework/ember/guides/linked-fields.md

@@ -16,8 +16,7 @@ To solve this, we need to make sure that the "confirm password" validation is re
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { createForm } from '@tanstack/ember-form';
 
 const handleChange = (field, event) => field.handleChange(event.target.value);

docs/framework/ember/guides/validation.md

@@ -17,8 +17,7 @@ Here is an example:
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { createForm } from '@tanstack/ember-form';
 
 const handleNumberInput = (field, event) =>

docs/framework/ember/quick-start.md

@@ -7,8 +7,6 @@ The bare minimum to get started with TanStack Form is to create a form and add a
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn } from '@ember/helper';
-import { on } from '@ember/modifier';
 import { createForm } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => field.handleChange(event.target.value);

packages/ember-form/README.md

@@ -16,8 +16,7 @@ pnpm add @tanstack/ember-form
 
 ```gjs
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { createForm, Field, Subscribe } from '@tanstack/ember-form';
 
 const handleInput = (field, event) => {

packages/ember-form/demo-app/templates/application.gts

@@ -1,6 +1,5 @@
 import Component from '@glimmer/component';
-import { fn, hash } from '@ember/helper';
-import { on } from '@ember/modifier';
+import { hash } from '@ember/helper';
 import { pageTitle } from 'ember-page-title';
 import { createForm, Subscribe } from '@tanstack/ember-form';