feat(web): patient web app with ЕМИАС (demo) and anonymous sign-in

A second channel to the same dialog engine as the Telegram bot: consent,
onboarding, scales and check-ins come from app/dialog; the bot is unchanged.

- API: /auth/emias (doctor's one-time connect code via EmiasMock),
  /auth/emias/demo (synthetic personas), /auth/anonymous (random token,
  nothing stored in the identity DB), /crisis/resources from crisis.yaml
- web/: React + TS + Vite, mobile-first, safe areas, hash routing,
  tokens and texts isolated for a Capacitor mobile build

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

web/src/screens/Welcome.tsx

@@ -0,0 +1,145 @@
+import { useNavigate } from "react-router-dom";
+
+import { AppShell } from "../components/AppShell";
+import { Icon } from "../components/Icon";
+import { ru } from "../content/ru";
+
+const SCALE = [1, 2, 3, 4, 5] as const;
+const WEEK = [38, 52, 46, 60, 58, 72, 80]; // illustrative trend, %
+
+function Facts({ items }: { items: readonly { ok: boolean; text: string }[] }) {
+  return (
+    <ul className="facts">
+      {items.map((f) => (
+        <li key={f.text} className={f.ok ? "fact" : "fact fact--no"}>
+          <Icon name={f.ok ? "check" : "minus"} size={18} />
+          <span>{f.text}</span>
+        </li>
+      ))}
+    </ul>
+  );
+}
+
+// Illustration of a day with the service (decorative: the same facts are stated in text).
+function DayPreview() {
+  const d = ru.welcome.day;
+  return (
+    <figure className="day" aria-hidden="true">
+      <figcaption className="day__caption">{d.caption}</figcaption>
+      <ol className="day__list">
+        <li className="day__item day__item--meds">
+          <span className="day__time">{d.meds.time}</span>
+          <div className="day__card">
+            <span className="day__track">
+              <Icon name="pill" size={16} />
+              {d.meds.track}
+            </span>
+            <div className="day__row">
+              <span className="day__text">{d.meds.text}</span>
+              <span className="day__done">
+                <Icon name="check" size={16} />
+                {d.meds.done}
+              </span>
+            </div>
+          </div>
+        </li>
+        <li className="day__item day__item--mood">
+          <span className="day__time">{d.mood.time}</span>
+          <div className="day__card">
+            <span className="day__track">
+              <Icon name="pulse" size={16} />
+              {d.mood.track}
+            </span>
+            <span className="day__text">{d.mood.text}</span>
+            <div className="scale">
+              {SCALE.map((n) => (
+                <span key={n} className={`scale__dot scale__dot--${n}${n === 4 ? " is-picked" : ""}`}>
+                  {n}
+                </span>
+              ))}
+            </div>
+            <div className="scale__ends">
+              <span>{d.mood.low}</span>
+              <span>{d.mood.high}</span>
+            </div>
+          </div>
+        </li>
+        <li className="day__item day__item--doctor">
+          <span className="day__time">{d.doctor.time}</span>
+          <div className="day__card">
+            <span className="day__track">
+              <Icon name="doctor" size={16} />
+              {d.doctor.track}
+            </span>
+            <div className="day__row">
+              <span className="day__text">{d.doctor.text}</span>
+              <span className="spark">
+                {WEEK.map((v, i) => (
+                  <i key={i} style={{ height: `${v}%` }} />
+                ))}
+              </span>
+            </div>
+          </div>
+        </li>
+      </ol>
+    </figure>
+  );
+}
+
+export function Welcome() {
+  const navigate = useNavigate();
+  const t = ru.welcome;
+
+  return (
+    <AppShell>
+      <main className="welcome" id="main">
+        <div className="welcome__inner">
+          <section className="welcome__intro" aria-labelledby="welcome-title">
+            <h1 id="welcome-title" className="display">
+              {t.title}
+            </h1>
+            <p className="lead">{t.lead}</p>
+          </section>
+
+          <section className="signin" aria-labelledby="choice-title">
+            <h2 id="choice-title" className="signin__title">
+              {t.choose}
+            </h2>
+
+            <article className="option option--emias">
+              <div className="option__head">
+                <span className="option__icon">
+                  <Icon name="doctor" size={22} />
+                </span>
+                <h3 className="option__title">{t.emias.title}</h3>
+                <span className="badge">{t.emias.badge}</span>
+              </div>
+              <Facts items={t.emias.facts} />
+              <button type="button" className="btn btn--primary btn--block" onClick={() => navigate("/emias")}>
+                {t.emias.action}
+              </button>
+            </article>
+
+            <article className="option option--anon">
+              <div className="option__head">
+                <span className="option__icon">
+                  <Icon name="lock" size={22} />
+                </span>
+                <h3 className="option__title">{t.anonymous.title}</h3>
+              </div>
+              <Facts items={t.anonymous.facts} />
+              <button type="button" className="btn btn--secondary btn--block" onClick={() => navigate("/anonymous")}>
+                {t.anonymous.action}
+              </button>
+            </article>
+          </section>
+
+          <div className="welcome__aside">
+            <DayPreview />
+            <p className="disclaimer">{t.disclaimer}</p>
+          </div>
+        </div>
+      </main>
+    </AppShell>
+  );
+}