Refactor GrampsWeb subpath handling: move all patching to nginx sub_filter (STI-98)

Replace fragile container-side sed/JS patching with comprehensive nginx sub_filter
rules. The container now only handles admin user creation on startup. All SPA route
prefixing is done in nginx via a History API interceptor injected into HTML responses.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

compose.yml

@@ -197,56 +197,16 @@ services:
       - GRAMPSWEB_ADMIN_EMAIL=${GRAMPSWEB_ADMIN_EMAIL:-admin@localhost}
       - GRAMPSWEB_ADMIN_PASSWORD=${GRAMPSWEB_ADMIN_PASSWORD:-gramps_dev_password}
       - GRAMPSWEB_TREE=${GRAMPSWEB_TREE:-Stiftung}
-      - GRAMPSWEB_BASE_URL=${GRAMPSWEB_BASE_URL:-http://localhost:8090}
+      - GRAMPSWEB_BASE_URL=${GRAMPSWEB_BASE_URL:-https://vhtv-stiftung.de/ahnenforschung}
       - GRAMPSWEB_CELERY_CONFIG__broker_url=redis://redis:6379/0
       - GRAMPSWEB_CELERY_CONFIG__result_backend=redis://redis:6379/0
       - GRAMPSWEB_RATELIMIT_STORAGE_URI=redis://redis:6379/1
       - GRAMPSWEB_NEW_DB_BACKEND=sqlite
-      - GRAMPSWEB_SUBPATH=${GRAMPSWEB_SUBPATH:-/ahnenforschung}
     command:
       - sh
       - -c
       - |
-        if [ -n "$$GRAMPSWEB_SUBPATH" ] && [ "$$GRAMPSWEB_SUBPATH" != "/" ]; then
-          SUBPATH="$$GRAMPSWEB_SUBPATH"
-          case "$$SUBPATH" in */) ;; *) SUBPATH="$${SUBPATH}/" ;; esac
-          echo "[grampsweb] Patching static files for subpath $$SUBPATH ..."
-          find / -name index.html -path "*/gramps*" -o -name index.html -path "*/static/*" 2>/dev/null | while read f; do
-            if grep -q '<base href="/">' "$$f" 2>/dev/null; then
-              sed -i "s|<base href=\"/\">|<base href=\"$$SUBPATH\">|g" "$$f"
-              echo "[grampsweb]   patched base href: $$f"
-            fi
-          done
-          for f in /app/static/*.js; do
-            if [ -f "$$f" ] && grep -q '/api/' "$$f" 2>/dev/null; then
-              sed -i "s|\"/api/|\"$${SUBPATH}api/|g" "$$f"
-              sed -i 's|`/api/|`'"$${SUBPATH}"'api/|g' "$$f"
-              sed -i "s|\"/lang/|\"$${SUBPATH}lang/|g" "$$f"
-              sed -i 's|`/lang/|`'"$${SUBPATH}"'lang/|g' "$$f"
-              sed -i "s|\"/fonts/|\"$${SUBPATH}fonts/|g" "$$f"
-              sed -i 's|`/fonts/|`'"$${SUBPATH}"'fonts/|g' "$$f"
-              sed -i "s|\"/assets/|\"$${SUBPATH}assets/|g" "$$f"
-              sed -i 's|`/assets/|`'"$${SUBPATH}"'assets/|g' "$$f"
-              sed -i "s|location\.href=\"/\"|location.href=\"$$SUBPATH\"|g" "$$f"
-              sed -i "s|document\.location\.href=\"/\"|document.location.href=\"$$SUBPATH\"|g" "$$f"
-              echo "[grampsweb]   patched JS paths: $$f"
-            fi
-          done
-          if [ -f /app/static/sw.js ]; then
-            sed -i "s|createHandlerBoundToURL(\"/index.html\")|createHandlerBoundToURL(\"$${SUBPATH}index.html\")|g" /app/static/sw.js
-            SUBPATH_BS=$$(echo "$$SUBPATH" | sed "s|/|\\\\\\\\/|g")
-            sed -i "s|\\^\\\\/api|\\^$${SUBPATH_BS}api|g" /app/static/sw.js
-            echo "[grampsweb]   patched sw.js navigation routes"
-          fi
-          find /app/static -name '*.css' 2>/dev/null | while read f; do
-            if grep -q '\.\./fonts/' "$$f" 2>/dev/null; then
-              sed -i "s|'../fonts/|'fonts/|g" "$$f"
-              sed -i "s|\"../fonts/|\"fonts/|g" "$$f"
-              echo "[grampsweb]   patched CSS font paths: $$f"
-            fi
-          done
-          echo "[grampsweb] Done."
-        fi
+        # All subpath rewriting is handled by nginx sub_filter — no container patching needed.
         echo "[grampsweb] Ensuring admin user exists ..."
         python3 << 'PYEOF' 2>&1 | grep -v Gtk
         from gramps_webapi.app import create_app