enrichment: Haiku flat details + image gallery on expand

apply service
- POST /internal/fetch-listing: headless Playwright fetch of a listing URL,
  returns {html, image_urls[], final_url}. Uses the same browser
  fingerprint/profile as the apply run so bot guards don't kick in

web service
- New enrichment pipeline (web/enrichment.py):
  /internal/flats → upsert → kick() enrichment in a background thread
    1. POST /internal/fetch-listing on apply
    2. llm.extract_flat_details(html, url) — Haiku tool-use call returns
       structured JSON (address, rooms, rent, description, pros/cons, etc.)
    3. Download each image directly to /data/flats/<slug>/NN.<ext>
    4. Persist enrichment_json + image_count + enrichment_status on the flat
- llm.py: minimal Anthropic /v1/messages wrapper, no SDK
- DB migration v5 adds enrichment_json/_status/_updated_at + image_count
- Admin "Altbestand anreichern" button (POST /actions/enrich-all) queues
  backfill for all pending/failed rows; runs in a detached task
- GET /partials/wohnung/<id> renders _wohnung_detail.html
- GET /flat-images/<slug>/<n> serves the downloaded image

UI
- Chevron on each list row toggles an inline detail pane (HTMX fetch on
  first open, hx-preserve keeps it open across the 3–30 s polls)
- CSS .flat-gallery normalises image tiles to a 4/3 aspect with object-fit:
  cover so different source sizes align cleanly
- "analysiert…" / "?" chips on the list reflect enrichment_status

Config
- ANTHROPIC_API_KEY + ANTHROPIC_MODEL wired into docker-compose's web
  service (default model: claude-haiku-4-5-20251001)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

web/static/app.js

@@ -47,3 +47,37 @@ document.addEventListener("DOMContentLoaded", tick);
 document.body && document.body.addEventListener("htmx:afterSwap", tick);
 setInterval(updateCountdowns, 1000);
 setInterval(updateRelativeTimes, 5000);
+
+// Flat detail expand — lazily fetches /partials/wohnung/<id> into the sibling
+// .flat-detail container on first open, toggles visibility on subsequent clicks.
+// Event delegation survives HTMX swaps without re-binding on each poll.
+document.addEventListener("click", (ev) => {
+  const btn = ev.target.closest(".flat-expand-btn");
+  if (!btn) return;
+  const row = btn.closest(".flat-row");
+  if (!row) return;
+  const pane = row.querySelector(".flat-detail");
+  if (!pane) return;
+
+  if (btn.classList.contains("open")) {
+    pane.style.display = "none";
+    btn.classList.remove("open");
+    return;
+  }
+  btn.classList.add("open");
+  pane.style.display = "block";
+  if (pane.dataset.loaded) return;
+
+  pane.innerHTML = '<div class="px-4 py-5 text-sm text-slate-500">lädt…</div>';
+  const flatId = btn.dataset.flatId || "";
+  fetch("/partials/wohnung/" + encodeURIComponent(flatId),
+        { headers: { "HX-Request": "true" } })
+    .then((r) => r.text())
+    .then((html) => {
+      pane.innerHTML = html;
+      pane.dataset.loaded = "1";
+    })
+    .catch(() => {
+      pane.innerHTML = '<div class="px-4 py-5 text-sm text-slate-500">Detail konnte nicht geladen werden.</div>';
+    });
+});