feat(clients): add nim-allographer client with BaraDB driver support

- Pure Nim wire protocol client (async + sync, no C FFI)
- Query Builder: fluent API, SQL generator, execution, transactions
- Schema Builder: create/alter/drop tables, column operations
- Connection pool with aging and timeout handling
- ORM integration via compile-time DB_BARADB switch
- Tests: test_open, test_query
- Documentation: README.md, PLAN_BARADB.md

clients/nim-allographer/.github/workflows/nim.yml

@@ -0,0 +1,61 @@
+name: Build and test Nim
+
+# テストはPRだけ
+on:
+  pull_request:
+    paths-ignore:
+      - '*.md'
+      - 'documents/*'
+
+# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
+# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
+concurrency:
+  group: "test"
+  cancel-in-progress: false
+
+jobs:
+  # WIP でジョブがスキップされてもCIが失敗した扱いにならないようにするため
+  skip:
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo "Skip job"
+
+  # WIP がコミットメッセージに含まれているとジョブを起動しない
+  before:
+    runs-on: ubuntu-latest
+    if: "! contains(github.event.head_commit.message, 'WIP')"
+    steps:
+      - run: echo "no WIP"
+
+  test-on-docker-nim:
+    runs-on: ubuntu-latest
+    needs: before
+    strategy:
+      fail-fast: false
+      matrix:
+        nim-version:
+          - 2.0.16
+          - 2.2.8
+    env:
+      NIM_VERSION: ${{ matrix.nim-version }}
+    steps:
+      - uses: actions/checkout@v2
+      - name: Build docker image
+        run: docker compose -f compose.test.yaml build app
+      - name: Start dependencies
+        run: docker compose -f compose.test.yaml up -d postgres mysql mariadb surreal
+      - name: Test
+        run: docker compose -f compose.test.yaml run --rm --no-deps app nimble test
+
+
+  # アプリケーションの方を使うことにした
+  # https://github.com/marketplace/actions/release-drafter
+  # create-tag-draft:
+  #   runs-on: ubuntu-latest
+  #   if: github.ref == 'refs/heads/master'
+  #   needs:
+  #     - test-on-docker
+  #   steps:
+  #     - uses: release-drafter/release-drafter@v5.3.1
+  #       env:
+  #         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}