chore(geocoding): remove Pelias + close 3 bypass paths to public Nominatim

Pelias was retired from the Mac mini on 2026-04-28; photon-self
(self-hosted Photon on mana-gpu) has been the live primary since then.
This removes the now-dead Pelias adapter, config, tests, and the
services/mana-geocoding/pelias/ stack — the entire compose file, the
geojsonify_place_details.js patch, the setup.sh import script.

Provider chain is now `photon-self → photon → nominatim`. The chain
keeps its `privacy: 'local' | 'public'` split, sensitive-query
blocking, coord quantization, and aggressive caching unchanged.

Three direct calls to nominatim.openstreetmap.org that bypassed
mana-geocoding now route through the wrapper:

- citycorners/add-city + citycorners/cities/[slug]/add use the shared
  searchAddress() client (browser → same-origin proxy → mana-geocoding
  → photon-self).
- memoro mobile drops its OSM reverse-geocoding fallback entirely;
  Expo's on-device reverse-geocoding stays as the sole path. Routing
  through the wrapper would require a memoro-server proxy endpoint —
  a follow-up if Expo's quality proves insufficient.

Other behavioral changes:

- CACHE_PUBLIC_TTL_MS dropped from 7d → 1h. The long TTL was a
  privacy-amplification trick from the Pelias era; with photon-self
  serving the bulk of traffic, a transient cross-LAN blip was pinning
  cached fallback answers for days. 1h gives quick recovery.
- /health/pelias renamed to /health/photon-self; prometheus blackbox
  config + status-page generator updated.
- mana-geocoding container no longer needs `extra_hosts:
  host.docker.internal:host-gateway` (was only there for the
  Pelias-on-host-network era).

113 tests passing. CLAUDE.md rewritten to reflect the post-Pelias
architecture.

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

docker/prometheus/prometheus.yml

@@ -314,9 +314,9 @@ scrape_configs:
       - targets:
           # mana-geocoding's own health (Hono wrapper)
           - http://mana-geocoding:3018/health
-          # Upstream Pelias health, proxied through the wrapper so the
+          # Upstream photon-self health, proxied through the wrapper so the
           # blackbox-exporter doesn't need host.docker.internal access.
-          - http://mana-geocoding:3018/health/pelias
+          - http://mana-geocoding:3018/health/photon-self
           # mana-ai (Mission Runner) — internal-only, no CF tunnel.
           - http://mana-ai:3066/health
     relabel_configs: