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/csrf_protection_controller.ts

@@ -0,0 +1,129 @@
+const nameCheck = /^[-_a-zA-Z0-9]{4,22}$/;
+const tokenCheck = /^[-_/+a-zA-Z0-9]{24,}$/;
+
+interface TurboSubmitEventDetail {
+    formSubmission: {
+        formElement: HTMLFormElement;
+        fetchRequest: { headers: Record<string, string> };
+    };
+}
+
+const CSRF_FIELD_SELECTOR =
+    'input[data-controller="csrf-protection"], input[name="_csrf_token"]';
+
+// Generate and double-submit a CSRF token in a form field and a cookie, as defined by Symfony's SameOriginCsrfTokenManager
+// Use `form.requestSubmit()` to ensure that the submit event is triggered. Using `form.submit()` will not trigger the event
+// and thus this event-listener will not be executed.
+document.addEventListener('submit', function (event) {
+    generateCsrfToken(event.target as HTMLFormElement);
+}, true);
+
+// When @hotwired/turbo handles form submissions, send the CSRF token in a header in addition to a cookie
+// The `framework.csrf_protection.check_header` config option needs to be enabled for the header to be checked
+document.addEventListener('turbo:submit-start', function (event) {
+    const detail = (event as CustomEvent<TurboSubmitEventDetail>).detail;
+    const h = generateCsrfHeaders(detail.formSubmission.formElement);
+    Object.keys(h).forEach(function (k) {
+        detail.formSubmission.fetchRequest.headers[k] = h[k];
+    });
+});
+
+// When @hotwired/turbo handles form submissions, remove the CSRF cookie once a form has been submitted
+document.addEventListener('turbo:submit-end', function (event) {
+    const detail = (event as CustomEvent<TurboSubmitEventDetail>).detail;
+    removeCsrfToken(detail.formSubmission.formElement);
+});
+
+export function generateCsrfToken(formElement: HTMLFormElement): void {
+    const csrfField = formElement.querySelector<HTMLInputElement>(
+        CSRF_FIELD_SELECTOR,
+    );
+
+    if (!csrfField) {
+        return;
+    }
+
+    let csrfCookie = csrfField.getAttribute(
+        'data-csrf-protection-cookie-value',
+    );
+    let csrfToken = csrfField.value;
+
+    if (!csrfCookie && nameCheck.test(csrfToken)) {
+        csrfField.setAttribute(
+            'data-csrf-protection-cookie-value',
+            csrfCookie = csrfToken,
+        );
+        csrfField.defaultValue = csrfToken = btoa(
+            String.fromCharCode.apply(
+                null,
+                Array.from(
+                    (window.crypto ||
+                        (window as unknown as { msCrypto: Crypto }).msCrypto)
+                        .getRandomValues(new Uint8Array(18)),
+                ),
+            ),
+        );
+    }
+    csrfField.dispatchEvent(new Event('change', { bubbles: true }));
+
+    if (csrfCookie && tokenCheck.test(csrfToken)) {
+        const cookie = csrfCookie + '_' + csrfToken + '=' + csrfCookie +
+            '; path=/; samesite=strict';
+        document.cookie = window.location.protocol === 'https:'
+            ? '__Host-' + cookie + '; secure'
+            : cookie;
+    }
+}
+
+export function generateCsrfHeaders(
+    formElement: HTMLFormElement,
+): Record<string, string> {
+    const headers: Record<string, string> = {};
+    const csrfField = formElement.querySelector<HTMLInputElement>(
+        CSRF_FIELD_SELECTOR,
+    );
+
+    if (!csrfField) {
+        return headers;
+    }
+
+    const csrfCookie = csrfField.getAttribute(
+        'data-csrf-protection-cookie-value',
+    );
+
+    if (
+        tokenCheck.test(csrfField.value) && nameCheck.test(String(csrfCookie))
+    ) {
+        headers[String(csrfCookie)] = csrfField.value;
+    }
+
+    return headers;
+}
+
+export function removeCsrfToken(formElement: HTMLFormElement): void {
+    const csrfField = formElement.querySelector<HTMLInputElement>(
+        CSRF_FIELD_SELECTOR,
+    );
+
+    if (!csrfField) {
+        return;
+    }
+
+    const csrfCookie = csrfField.getAttribute(
+        'data-csrf-protection-cookie-value',
+    );
+
+    if (
+        tokenCheck.test(csrfField.value) && nameCheck.test(String(csrfCookie))
+    ) {
+        const cookie = String(csrfCookie) + '_' + csrfField.value +
+            '=0; path=/; samesite=strict; max-age=0';
+
+        document.cookie = window.location.protocol === 'https:'
+            ? '__Host-' + cookie + '; secure'
+            : cookie;
+    }
+}
+
+/* stimulusFetch: 'lazy' */
+export default 'csrf-protection-controller';