chore: refactor legacy JS init code to use "data-global-init" (#39836)

Move the remaining legacy init code, which probed page classes with
`querySelector`, to `data-global-init`, so each feature initializes from
its own element. `hashchange` listeners now go through one module that
runs them in priority order, because independent listeners broke when
mount order changed.

- Convert issue list, diff, repo create, settings and org team inits to
`data-global-init`
- Run `hashchange` listeners by priority, the diff scroll handler last
- Make the devtest mock's failing log requests deterministic
- Add e2e tests for diff tree navigation to folded files and job log
permalinks

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Co-authored-by: silverwind <me@silverwind.io>

web_src/js/modules/hashchange.ts

@@ -0,0 +1,25 @@
+type HashChangeListener = (e: HashChangeEvent) => void | Promise<void>;
+
+const hashChangeListeners: Array<{listener: HashChangeListener, priority: number}> = [];
+let hashChangeListenersInited = false;
+
+export function registerAsyncHashChangeListener(listener: HashChangeListener, priority = 0): void {
+  hashChangeListeners.push({listener, priority});
+  hashChangeListeners.sort((a, b) => a.priority - b.priority);
+  if (hashChangeListenersInited) listener(new HashChangeEvent('hashchange')); // late registrants missed the initial run
+}
+
+export function removeAsyncHashChangeListener(listener: HashChangeListener): void {
+  const index = hashChangeListeners.findIndex((item) => item.listener === listener);
+  if (index !== -1) hashChangeListeners.splice(index, 1);
+}
+
+async function runHashChangeListeners(e: HashChangeEvent) {
+  for (const {listener} of hashChangeListeners) await listener(e);
+}
+
+export async function initAsyncHashChangeListeners() {
+  hashChangeListenersInited = true;
+  window.addEventListener('hashchange', runHashChangeListeners);
+  await runHashChangeListeners(new HashChangeEvent('hashchange'));
+}