docs(02): research phase domain with Context7

Phase 02: Docker Integration
- Docker Engine API endpoints documented (Context7 /docker/docs)
- n8n Execute Command and Code node patterns (Context7 /n8n-io/n8n-docs)
- Custom Dockerfile needed for curl in n8n container
- Fuzzy matching and response formatting patterns

.planning/phases/02-docker-integration/02-RESEARCH.md

@@ -598,30 +598,27 @@ Things that couldn't be fully resolved:
 
 ## Sources
 
-### Primary (HIGH confidence)
+### Primary (HIGH confidence) — Context7 MCP
-- [Docker Engine API Official Documentation](https://docs.docker.com/reference/api/engine/) - API reference
+
-- [Docker Engine API Examples](https://docs.docker.com/reference/api/engine/sdk/examples/) - Official usage examples
+**Docker API** (`/docker/docs`):
-- [Docker inspect CLI documentation](https://docs.docker.com/reference/cli/docker/inspect/) - Container data structure
+- `GET /containers/json` — List containers with filtering (all, status, before, limit)
-- [Docker stats CLI documentation](https://docs.docker.com/reference/cli/docker/container/stats/) - Resource metrics
+- `GET /containers/(id)/stats` — Resource usage (memory_stats, cpu_stats, network)
-- [n8n Docker documentation](https://docs.n8n.io/hosting/installation/docker/) - n8n Docker setup
+- Container response schema: Id, Names, Image, State, Status, Ports, NetworkSettings
-- [n8n Docker Compose documentation](https://docs.n8n.io/hosting/installation/server-setups/docker-compose/) - Deployment examples
+- curl unix socket pattern: `curl --unix-socket /var/run/docker.sock http://localhost/v1.xx/containers/json`
-- [n8n Code node documentation](https://docs.n8n.io/code/code-node/) - JavaScript execution
+
-- [n8n Execute Command documentation](https://docs.n8n.io/integrations/builtin/core-nodes/n8n-nodes-base.executecommand/) - Shell command execution
+**n8n Documentation** (`/n8n-io/n8n-docs`):
+- Execute Command node — Disabled by default in n8n 2.0+, runs in container not host
+- Custom Dockerfile needed for curl: `FROM n8nio/n8n; USER root; RUN apk add curl; USER node`
+- Code node external modules: `NODE_FUNCTION_ALLOW_EXTERNAL=moment,uuid` environment variable
+- Built-in modules: `NODE_FUNCTION_ALLOW_BUILTIN=crypto` for Node.js builtins
 
 ### Secondary (MEDIUM confidence)
-- [Using curl with Docker Unix socket](https://sleeplessbeastie.eu/2021/12/13/how-to-query-docker-socket-using-curl/) - Practical curl examples
-- [Docker Engine API container info guide](https://www.baeldung.com/ops/docker-engine-api-container-info) - Comprehensive guide verified with official docs
-- [Docker stats in JSON format](https://kylewbanks.com/blog/docker-stats-memory-cpu-in-json-format) - Stats parsing examples
-- [n8n Execute Command tutorial](https://logicworkflow.com/nodes/execute-command-node/) - Usage patterns
 - [Fuse.js official documentation](https://www.fusejs.io/) - Fuzzy matching library
 - [fast-fuzzy npm package](https://www.npmjs.com/package/fast-fuzzy) - Lightweight alternative
-- [n8n modules in Code node](https://docs.n8n.io/hosting/configuration/configuration-examples/modules-in-code-node/) - External package setup
 
 ### Tertiary (LOW confidence)
-- [n8n community: Docker commands from n8n](https://community.n8n.io/t/can-i-run-docker-command-from-n8n/19659) - Community discussion, verify approaches
 - [Docker socket security considerations](https://0xn3va.gitbook.io/cheat-sheets/container/escaping/exposed-docker-socket) - Security implications
 - [Container escape mitigation](https://www.startupdefense.io/cyberattacks/docker-escape) - Security best practices
-- [Docker container naming conventions](https://devtodevops.com/blog/docker-container-naming-convention/) - Community practices
 
 ## Metadata