test: drive the Lance namespace with LanceDB

The Iceberg catalog is checked against Spark, Trino, ClickHouse, Doris,
Dremio and RisingWave. The Lance one had only its own reference client,
which is the same thing as checking it against ourselves.

LanceDB connects with connect_namespace("rest", ...), which speaks the
routes this catalog implements, so the suite exercises the protocol rather
than our idea of it: list the catalog, open a table through it, read the
schema, run a vector search and a filtered scan, create a table, and read
the same dataset straight off its URI with no catalog at all.

    table_names -> ['lancedb-p0guidmm$ml$embeddings']
    open_table  -> 64 rows
    search      -> [1, 0, 2]
    create_table -> 4 rows, listed by the catalog
    direct read without the catalog -> 64 rows

Seeding is pylance, because the namespace records where a table lives and
does not carry its data. That split is the design rather than a limit of
the test.

One interop note the test encodes: a gateway without STS vends
storage_options carrying an endpoint and a region but no credentials, and
LanceDB uses what the namespace vends on some paths. The container gets
credentials in its environment as well, which is what a deployment without
STS would do.

Claude-Session: https://claude.ai/code/session_01Rkp1Mw5E89Jp6dzJFYiMrm

.github/workflows/s3-tables-tests.yml

@@ -874,6 +874,76 @@ jobs:
           path: test/s3tables/unity_catalog/test-output.log
           retention-days: 3
 
+  lancedb-namespace-tests:
+    name: LanceDB Namespace Integration Tests
+    runs-on: ubuntu-22.04
+    timeout-minutes: 30
+
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v7
+
+      - name: Set up Go
+        uses: actions/setup-go@v7
+        with:
+          go-version-file: 'go.mod'
+        id: go
+
+      - name: Configure Docker Hub mirror
+        run: |
+          echo '{"registry-mirrors": ["https://mirror.gcr.io"]}' | sudo tee /etc/docker/daemon.json
+          sudo systemctl restart docker
+
+      - name: Pre-pull images
+        run: |
+          pull() { for i in 1 2 3; do docker pull "$1" && return 0; sleep 15; done; return 1; }
+          pull python:3.11-slim
+
+      - name: Run go mod tidy
+        run: go mod tidy
+
+      - name: Build SeaweedFS
+        run: |
+          cd weed && go build -buildvcs=false .
+
+      - name: Run LanceDB Namespace Integration Tests
+        timeout-minutes: 25
+        working-directory: test/s3tables/catalog_lancedb
+        run: |
+          set -x
+          set -o pipefail
+          echo "=== System Information ==="
+          uname -a
+          free -h
+          df -h
+          docker info
+          echo "=== Starting LanceDB Namespace Tests ==="
+
+          go test -v -timeout 20m . 2>&1 | tee test-output.log || {
+            echo "LanceDB namespace integration tests failed"
+            exit 1
+          }
+
+      - name: Show test output on failure
+        if: failure()
+        working-directory: test/s3tables/catalog_lancedb
+        run: |
+          echo "=== Test Output ==="
+          if [ -f test-output.log ]; then
+            tail -200 test-output.log
+          fi
+
+          echo "=== Process information ==="
+          ps aux | grep -E "(weed|test|docker)" || true
+
+      - name: Upload test logs on failure
+        if: failure()
+        uses: actions/upload-artifact@v7
+        with:
+          name: lancedb-namespace-test-logs
+          path: test/s3tables/catalog_lancedb/test-output.log
+          retention-days: 3
+
   s3-tables-build-verification:
     name: S3 Tables Build Verification
     runs-on: ubuntu-22.04