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/dashboard/usage.html

@@ -0,0 +1,29 @@
+{% extends "base.html" %}
+{% block title %}Potrošnja — {{ owner.tenant.name }}{% endblock %}
+{% block nav %}{% include "dashboard/_nav.html" %}{% endblock %}
+{% block content %}
+<h1>Potrošnja — {{ usage.month }}</h1>
+<div class="card">
+  <h2>Minute virtualnog asistenta</h2>
+  <div class="bar"><div class="{{ 'over' if usage.over_100 else ('warn' if usage.over_80 else '') }}"
+       style="width:{{ usage.pct }}%"></div></div>
+  <p><b>{{ usage.used_minutes }}</b> od <b>{{ usage.included_minutes }}</b> uključenih minuta
+  ({{ usage.pct }}%)</p>
+  {% if usage.over_100 %}
+  <div class="banner">Prekoračili ste uključene minute. Asistent i dalje odgovara na pozive —
+  javiće vam se Gogo tim oko proširenja paketa.</div>
+  {% endif %}
+  <p class="muted">Vrijeme kad se javi vaše osoblje ne troši minute; chat se ne naplaćuje po
+  minutama.</p>
+</div>
+<div class="grid3">
+  <div class="card"><h2>Pozivi asistenta</h2><p style="font-size:28px;margin:0"><b>{{ usage.calls }}</b></p></div>
+  <div class="card"><h2>Poslani SMS</h2><p style="font-size:28px;margin:0"><b>{{ usage.sms_sent }}</b></p></div>
+  <div class="card"><h2>Chat razgovori</h2><p style="font-size:28px;margin:0"><b>{{ usage.chat_sessions }}</b></p></div>
+</div>
+{% if owner.tenant.paid_until %}
+<div class="card"><h2>Pretplata</h2>
+<p>Plaćeno do: <b>{{ owner.tenant.paid_until.strftime('%d.%m.%Y.') }}</b> —
+paket „Gogo Start" ({{ owner.tenant.included_minutes }} min/mj).</p></div>
+{% endif %}
+{% endblock %}