recon: remove /api/config handler (now served by navi-config, extraction #2)

Completes the recon-side cleanup for extraction #2. /api/config has been
served by the standalone navi-config service (:8422) in production since the
Caddy cutover on 2026-05-22 — public traffic to navi.echo6.co/api/config now
flows Caddy -> nginx :8440 -> navi-config :8422, never reaching recon. The
handler here was dead code.

Removes only the @app.route('/api/config') route + api_config() function.

KEPT (deliberately): lib/deployment_config.py and the
`from .deployment_config import get_deployment_config` import in lib/api.py.
get_deployment_config() is still used by other recon code:
  - lib/api.py            api_landclass (/api/landclass)
  - lib/google_places.py
  - lib/offroute/router.py
  - lib/place_detail.py   (4 call sites)
So the loader stays; only the now-duplicated HTTP route is removed.

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

lib/api.py

@@ -1255,15 +1255,6 @@ def api_landclass():
     })
 
 
-@app.route('/api/config')
-def api_config():
-    """Return deployment profile config for frontend consumption."""
-    config = get_deployment_config()
-    resp = jsonify(config)
-    resp.headers['Cache-Control'] = 'public, max-age=300'
-    return resp
-
-
 @app.route('/api/health')
 def api_health():
     """Health check endpoint for monitoring."""