feat(ebook): add Docker packaging and lifecycle tooling

Add a self-contained docker/ package for running the ebook search app
against the existing Postgres database on jeeves:

- Dockerfile: python:3.14-slim image, non-root user, runs the FastAPI
  app on port 8070
- docker-compose.yml: service definition with library volume mount,
  BM25 index volume, .env loading, and a /health healthcheck
- containers.py: Typer CLI (ebook-search-containers) for build/start/
  stop/restart/logs/ps lifecycle management
- README.md: usage and configuration docs

python/ebook_search/docker/docker-compose.yml

@@ -0,0 +1,36 @@
+name: ebook-search
+
+services:
+  ebook-search:
+    build:
+      context: ../../..
+      dockerfile: python/ebook_search/docker/Dockerfile
+    image: ebook-search:latest
+    restart: unless-stopped
+    ports:
+      - "${EBOOK_SEARCH_PORT:-8070}:8070"
+    extra_hosts:
+      - "jeeves:192.168.90.40"
+    env_file:
+      - ../../../.env
+    environment:
+      EBOOK_SEARCH_HOST: "0.0.0.0"
+      EBOOK_SEARCH_PORT: "8070"
+      EBOOK_SEARCH_LIBRARY_PATHS: "/library"
+      EBOOK_SEARCH_BM25_INDEX_DIR: "/data/bm25"
+    volumes:
+      - "${EBOOK_LIBRARY_HOST_PATH:-/home/richie/ebooks}:/library:ro"
+      - ebook-search-data:/data
+    healthcheck:
+      test:
+        [
+          "CMD-SHELL",
+          "curl -fsS http://127.0.0.1:8070/health >/dev/null || exit 1",
+        ]
+      interval: 30s
+      timeout: 5s
+      retries: 5
+      start_period: 30s
+
+volumes:
+  ebook-search-data: