Add EPI-Support monitoring & analytics platform

Internal Flask app that monitors the epi-helpdesk.zammad.com tickets via
the Zammad API, deployable as a systemd service behind Apache under
/episupport.

Features:
- Poller: session-login API sync, snapshot diff to detect agent changes
  (status, owner, priority, closures, new replies); email notifications
- Dashboard: ticket overview with sorting, "not closed" filter and
  highlighting of tickets with unconfirmed changes; per-item and bulk
  "mark as read"
- Analytics: KPIs, response/resolution times, monthly SVG trend chart,
  distributions (status/priority/group/agent), Excel export
- Conversation view: full per-ticket thread cached in the DB (avoids
  proxy timeouts), inline image attachments, safe HTML-to-text rendering
- Write actions: reply to tickets and create new tickets with a
  confirmation step and attachment upload (incl. clipboard paste);
  self-triggered actions are synced back so they aren't flagged as changes
- Local timezone display (Europe/Berlin) for all timestamps

Includes deploy tooling: setup.sh, systemd units and Apache config.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

static/style.css

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+.msg-imgs { margin-top: .6rem; display: flex; flex-wrap: wrap; gap: .5rem; }
+.msg-img {
+  max-width: 260px; max-height: 260px; border: 1px solid var(--line);
+  border-radius: 8px; object-fit: contain; background: #fff; cursor: zoom-in;
+}
 
 /* --- Formulare / Antworten --- */
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@@ -208,3 +213,21 @@ textarea { resize: vertical; }
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 .btn-ghost { padding: .55rem 1rem; border-radius: 7px; border: 1px solid var(--line); color: #44525e; font-size: .9rem; }
+
+/* --- Anhänge --- */
+.attach { display: flex; flex-direction: column; gap: .4rem; }
+.attach-label { font-size: .85rem; font-weight: 600; color: #44525e; display: flex; flex-direction: column; gap: .15rem; }
+.attach-hint { font-weight: 400; color: var(--muted); font-size: .78rem; }
+.attach-input { font: inherit; font-size: .82rem; }
+.attach-list { display: flex; flex-wrap: wrap; gap: .4rem; }
+.attach-chip {
+  display: inline-flex; align-items: center; gap: .3rem; background: #eef2f5;
+  border: 1px solid var(--line); border-radius: 999px; padding: .15rem .6rem;
+  font-size: .8rem; color: #44525e;
+}
+.attach-chip button {
+  border: 0; background: transparent; color: var(--accent); cursor: pointer;
+  font-size: 1rem; line-height: 1; padding: 0;
+}
+.attach-form.dragging { outline: 2px dashed var(--brand); outline-offset: 4px; border-radius: 8px; }
+.attach-summary { margin: .4rem 0 .2rem; display: flex; flex-wrap: wrap; gap: .4rem; align-items: center; font-size: .85rem; }