Web dashboard step 1: migration, sessions, users CLI, public site

Migration 0004 (users, sessions, config_changes, profile_versions, jobs,
rating_events.user_id, runs.report_json, issues.issue_json), the issue
snapshot writer and loader, the web module skeleton with layout and static
assets, axum-login/tower-sessions over a sqlx session store, password-auth
users with a CLI, the login throttle, the origin check, security headers,
and the public issue pages, archive, Atom feed and robots.txt.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NHyYupFdBiR4VfoUM7NjSM

src/web/static/app.js

@@ -0,0 +1,11 @@
+document.addEventListener("submit", (event) => {
+  const message = event.target.dataset.confirm;
+  if (message && !window.confirm(message)) event.preventDefault();
+});
+document.querySelectorAll("details[id]").forEach((details) => {
+  try {
+    const key = "details:" + details.id;
+    details.open = localStorage.getItem(key) === "open";
+    details.addEventListener("toggle", () => localStorage.setItem(key, details.open ? "open" : "closed"));
+  } catch (_) {}
+});