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/app.py

@@ -15,6 +15,7 @@ import hmac
 import io
 import json
 import logging
+import mimetypes
 import sqlite3
 import zipfile
 from contextlib import asynccontextmanager
@@ -33,6 +34,7 @@ except Exception:
     BERLIN_TZ = timezone.utc
 
 import db
+import enrichment
 import notifications
 import retention
 from apply_client import ApplyClient, _row_to_profile
@@ -119,6 +121,7 @@ def _iso_utc(s: str | None) -> str:
 
 templates.env.filters["de_dt"] = _de_dt
 templates.env.filters["iso_utc"] = _iso_utc
+templates.env.filters["flat_slug"] = lambda s: enrichment.flat_slug(str(s or ""))
 
 
 @app.middleware("http")
@@ -473,6 +476,53 @@ def partial_wohnungen(request: Request, user=Depends(require_user)):
     return templates.TemplateResponse("_wohnungen_body.html", ctx)
 
 
+@app.get("/partials/wohnung/{flat_id:path}", response_class=HTMLResponse)
+def partial_wohnung_detail(request: Request, flat_id: str, user=Depends(require_user)):
+    flat = db.get_flat(flat_id)
+    if not flat:
+        raise HTTPException(404)
+    enrichment_data = None
+    if flat["enrichment_json"]:
+        try:
+            enrichment_data = json.loads(flat["enrichment_json"])
+        except Exception:
+            enrichment_data = None
+    slug = enrichment.flat_slug(flat_id)
+    image_urls = [
+        f"/flat-images/{slug}/{i}"
+        for i in range(1, int(flat["image_count"] or 0) + 1)
+    ]
+    ctx = {
+        "request": request,
+        "flat": flat,
+        "enrichment": enrichment_data,
+        "enrichment_status": flat["enrichment_status"],
+        "image_urls": image_urls,
+    }
+    return templates.TemplateResponse("_wohnung_detail.html", ctx)
+
+
+@app.get("/flat-images/{slug}/{index}")
+def flat_image(slug: str, index: int):
+    """Serve a downloaded flat image by slug + 1-based index.
+
+    `slug` is derived from enrichment.flat_slug(flat_id) and is filesystem-safe
+    (hex), so it can be composed into a path without sanitisation concerns."""
+    if not slug.isalnum() or not 1 <= index <= 99:
+        raise HTTPException(404)
+    d = enrichment.IMAGES_DIR / slug
+    if not d.exists():
+        raise HTTPException(404)
+    # Files are named NN.<ext>; try the usual extensions.
+    prefix = f"{index:02d}."
+    for f in d.iterdir():
+        if f.name.startswith(prefix):
+            media = mimetypes.guess_type(f.name)[0] or "image/jpeg"
+            return Response(content=f.read_bytes(), media_type=media,
+                            headers={"Cache-Control": "public, max-age=3600"})
+    raise HTTPException(404)
+
+
 @app.post("/actions/filters")
 async def action_save_filters(
     request: Request,
@@ -974,6 +1024,19 @@ async def action_users_disable(
     return RedirectResponse("/einstellungen/benutzer", status_code=303)
 
 
+@app.post("/actions/enrich-all")
+async def action_enrich_all(
+    request: Request,
+    csrf: str = Form(...),
+    admin=Depends(require_admin),
+):
+    require_csrf(admin["id"], csrf)
+    queued = enrichment.kick_backfill()
+    db.log_audit(admin["username"], "enrichment.backfill",
+                 f"queued={queued}", user_id=admin["id"], ip=client_ip(request))
+    return _wohnungen_partial_or_redirect(request, admin)
+
+
 @app.post("/actions/users/delete")
 async def action_users_delete(
     request: Request,
@@ -1010,6 +1073,9 @@ async def internal_submit_flat(
     if not is_new:
         return {"status": "duplicate"}
 
+    # Kick LLM enrichment + image download for this fresh flat.
+    enrichment.kick(str(payload["id"]))
+
     for u in db.list_users():
         if u["disabled"]:
             continue