feat: stats-based pruning, workbench UI, and instance-level S3 config (Phase 3)

Replace predicate partitioning with flat files and per-file min/max stats
for pruning. Add S3 Store to RDF4J Workbench with creation form and TTL
config template. S3 connection settings (bucket, endpoint, credentials)
resolve from environment variables (RDF4J_S3_*) or system properties so
multiple repositories share a single bucket, each isolated by s3Prefix.

Author: odysa

core/repository/api/src/main/resources/org/eclipse/rdf4j/repository/config/s3.ttl

@@ -0,0 +1,25 @@
+#
+# Configuration template for an S3Store
+#
+# S3 connection settings (bucket, endpoint, region, credentials) are configured
+# at the RDF4J instance level via environment variables or system properties:
+#
+#   RDF4J_S3_BUCKET, RDF4J_S3_ENDPOINT, RDF4J_S3_REGION,
+#   RDF4J_S3_ACCESS_KEY, RDF4J_S3_SECRET_KEY, RDF4J_S3_FORCE_PATH_STYLE
+#
+# Each repository uses s3Prefix to partition its data within the shared bucket.
+#
+@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#>.
+@prefix config: <tag:rdf4j.org,2023:config/>.
+@prefix s3: <http://rdf4j.org/config/sail/s3#>.
+
+[] a config:Repository ;
+   config:rep.id "{%Repository ID|s3%}" ;
+   rdfs:label "{%Repository title|S3 Store%}" ;
+   config:rep.impl [
+      config:rep.type "openrdf:SailRepository" ;
+      config:sail.impl [
+         config:sail.type "rdf4j:S3Store" ;
+         s3:s3Prefix "{%S3 Prefix|%}"
+      ]
+   ].

core/sail/s3/docker-compose.yml

@@ -0,0 +1,32 @@
+services:
+  minio:
+    image: minio/minio:latest
+    ports:
+      - "9000:9000"
+      - "9001:9001"
+    environment:
+      MINIO_ROOT_USER: minioadmin
+      MINIO_ROOT_PASSWORD: minioadmin
+    command: server /data --console-address ":9001"
+    volumes:
+      - minio-data:/data
+    healthcheck:
+      test: ["CMD", "mc", "ready", "local"]
+      interval: 5s
+      timeout: 5s
+      retries: 5
+
+  createbucket:
+    image: minio/mc:latest
+    depends_on:
+      minio:
+        condition: service_healthy
+    entrypoint: >
+      /bin/sh -c "
+      mc alias set local http://minio:9000 minioadmin minioadmin;
+      mc mb --ignore-existing local/rdf4j-data;
+      echo 'Bucket ready';
+      "
+
+volumes:
+  minio-data: