Migrate frontend to TypeScript with Deno-based tooling (#209)

* Migrate frontend to TypeScript with Deno-based tooling (#206)

Compiles assets/*.ts via sensiolabs/typescript-bundle (standalone SWC
binary) and adds Deno for formatting, linting, type-checking, and
tests, keeping the project's no-Node/npm approach intact. Wires all
four into CI, the Justfile, and the pre-commit hook.

* fix: build TypeScript assets before running PHPUnit in CI

The tests job ran bin/console sass:build but never typescript:build,
so var/typescript/ didn't exist and any page rendering the importmap
(e.g. backoffice/base.html.twig) errored during tests.

* test: add regression test for backoffice navbar-toggler dead target

Guards against the navbar-toggler button pointing at a collapse
target (#navbarSupportedContent) that isn't rendered for the current
user — the bug hit on the login page before #210 restructured the
nav to always render at least one item (the Releases link) regardless
of auth state.

* fix: stop hand-enumerating TS files for deno check

deno check assets/*.ts assets/controllers/*.ts assets/controllers/bo/*.ts
was duplicated in CI and the Justfile, and silently misses any new
controller subdirectory (fmt/lint/test already recurse assets/ via
deno.json). Add a top-level exclude for assets/vendor/ (respected by
all deno subcommands, unlike the per-task include/exclude blocks) so
deno check assets/ can recurse safely instead.

* fix: GitHubReleasesService date parsing and falsy release name

- Move the release-mapping array_map inside the try block so a
  malformed published_at (or any other parse failure) degrades to the
  same empty-list fallback as an HTTP failure, instead of throwing
  uncaught out of the cache callback.
- Stop treating a release literally named "0" as unnamed — the old
  `?:` fallback is falsy for that string and silently substituted the
  tag name instead.
- Render release dates in UTC explicitly; Twig's date filter otherwise
  silently converts to the app's default timezone (Europe/Amsterdam),
  which could show the wrong calendar day for releases near midnight.

* docs: add scope-creep-as-a-service rule to CLAUDE.md

Per user instruction: when a review turns up a real bug outside the
current task's scope, fix it in the same MR (with a regression test)
rather than just reporting it, unless it needs a human design call.

assets/controllers/bo/form_collection_controller_test.ts

@@ -0,0 +1,114 @@
+import { assertEquals } from '@std/assert';
+
+// Stimulus's Controller base class constructor only does `this.context = context`,
+// and target getters are normally installed by Application.register — since we
+// construct the controller directly (no real Stimulus app), collectionTarget/element
+// are assigned here as plain writable properties, backed by a minimal fake DOM
+// container that supports the one operation these methods actually rely on:
+// appendChild() moving an existing child to the end (real DOM semantics).
+class FakeInput {
+    value: string;
+    constructor(value = '') {
+        this.value = value;
+    }
+}
+
+class FakeItem {
+    textInput: FakeInput;
+    orderingInput = new FakeInput();
+
+    constructor(text: string) {
+        this.textInput = new FakeInput(text);
+    }
+
+    querySelector<T>(selector: string): T | null {
+        if (selector.includes('type="text"')) {
+            return this.textInput as unknown as T;
+        }
+        if (selector.includes('ordering')) {
+            return this.orderingInput as unknown as T;
+        }
+        return null;
+    }
+}
+
+class FakeCollection {
+    children: FakeItem[] = [];
+
+    appendChild(item: FakeItem) {
+        const idx = this.children.indexOf(item);
+        if (idx !== -1) this.children.splice(idx, 1);
+        this.children.push(item);
+    }
+}
+
+const { default: FormCollectionController } = await import(
+    './form_collection_controller.ts'
+);
+
+// deno-lint-ignore no-explicit-any
+function makeController(items: FakeItem[]): any {
+    const collectionTarget = new FakeCollection();
+    collectionTarget.children = items;
+    // `element` is a read-only getter on Controller (delegates to `this.scope.element`),
+    // so the fake element is supplied via the constructor context rather than assigned.
+    const controller = new FormCollectionController({
+        scope: { element: { dispatchEvent: () => true } },
+    } as never);
+    return Object.assign(controller, { collectionTarget });
+}
+
+Deno.test("_syncOrdering writes the current index into each item's ordering input", () => {
+    const items = [new FakeItem('c'), new FakeItem('a'), new FakeItem('b')];
+    const controller = makeController(items);
+
+    controller._syncOrdering();
+
+    assertEquals(items.map((i) => i.orderingInput.value), ['0', '1', '2']);
+});
+
+Deno.test('sortAlphabetically reorders items by their text input value, case-insensitively', () => {
+    const c = new FakeItem('Charlie');
+    const a = new FakeItem('alice');
+    const b = new FakeItem('Bob');
+    const controller = makeController([c, a, b]);
+
+    controller.sortAlphabetically();
+
+    assertEquals(
+        controller.collectionTarget.children.map((i: FakeItem) =>
+            i.textInput.value
+        ),
+        ['alice', 'Bob', 'Charlie'],
+    );
+    // _syncOrdering must run after the reorder, against the new order
+    assertEquals(
+        controller.collectionTarget.children.map((i: FakeItem) =>
+            i.orderingInput.value
+        ),
+        ['0', '1', '2'],
+    );
+});
+
+Deno.test('randomize keeps the same set of items and resyncs ordering', () => {
+    const items = [
+        new FakeItem('1'),
+        new FakeItem('2'),
+        new FakeItem('3'),
+        new FakeItem('4'),
+    ];
+    const controller = makeController([...items]);
+
+    controller.randomize();
+
+    const resultValues = controller.collectionTarget.children.map((
+        i: FakeItem,
+    ) => i.textInput.value);
+    assertEquals(resultValues.slice().sort(), ['1', '2', '3', '4']);
+    assertEquals(
+        controller.collectionTarget.children.map((i: FakeItem) =>
+            i.orderingInput.value
+        ),
+        ['0', '1', '2', '3'],
+    );
+});