M3: chat widget, owner dashboard, super-admin panel

- Embeddable vanilla-JS chat widget (one script tag + tenant public key):
  WebSocket, resumable sessions (24h localStorage token), honeypot + per-IP
  and per-message rate limits, Bosnian UI (§7)
- Session auth (bcrypt + signed cookies), owner accounts + super-admins,
  admin impersonation ('otvori kao salon', §11)
- Owner dashboard (§10, Bosnian): requests with same actions as email,
  call/chat history with transcripts, usage bar; settings for profile,
  working hours (manual + LLM paste-to-parse), services CRUD + 'Zalijepi
  cjenovnik' LLM import with review step, scheduling (Google OAuth free/busy
  read-only + calendar mappings + buffers, partner status), telephony
  (forwarding MMI codes per operator, ring group, worker SIP creds + QR),
  agent voice/price-mode/notes + widget snippet, notifications/SMS templates
- Super-admin panel (§11): tenant CRUD incl. plan/minutes/paid-until,
  partner API config (encrypted secrets), number/SIM registry + assignment,
  connectivity test (live availability + dry-run push), versioned prompt
  template editor with publish/rollback, playground, usage overview, health
- Fixes: WAL + busy_timeout for sqlite tests, no awaits in WS disconnect
  path (deadlock), template publish autoflush bug
- 76 tests green (incl. widget WS e2e booking flow); dashboard, widget and
  admin verified live in a browser against Postgres

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

gogo/templates/admin/usage.html

@@ -0,0 +1,26 @@
+{% extends "base.html" %}
+{% block title %}Potrošnja — Gogo Admin{% endblock %}
+{% block nav %}{% include "admin/_nav.html" %}{% endblock %}
+{% block content %}
+<h1>Potrošnja po salonima — {{ month }}</h1>
+<div class="card">
+<table>
+  <tr><th>Salon</th><th>Minute asistenta</th><th>Pozivi</th><th>SMS</th><th>Chat</th>
+      <th>Zahtjevi (mj)</th><th>Procj. trošak (LLM+TTS)</th></tr>
+  {% for r in rows %}
+  <tr>
+    <td><b>{{ r.tenant.name }}</b></td>
+    <td>{{ r.used_minutes }}/{{ r.tenant.included_minutes }}
+      {% if r.over_100 %}<span class="badge rejected">100%+</span>
+      {% elif r.over_80 %}<span class="badge pending">80%+</span>{% endif %}</td>
+    <td>{{ r.calls }}</td>
+    <td>{{ r.sms }}</td>
+    <td>{{ r.chats }}</td>
+    <td>{{ r.requests }}</td>
+    <td>~{{ r.est_cost_km }} KM</td>
+  </tr>
+  {% endfor %}
+</table>
+<p class="muted">Procjena troška: {{ cost_note }}</p>
+</div>
+{% endblock %}