feat(skills): add research-summarizer and docker-development agent skills

research-summarizer (product-team/):
- Structured research summarization for papers, articles, reports
- Slash commands: /research:summarize, /research:compare, /research:cite
- Python tools: extract_citations.py (5 citation formats), format_summary.py (6 templates)
- References: summary-templates.md, citation-formats.md

docker-development (engineering/):
- Dockerfile optimization, compose orchestration, container security
- Slash commands: /docker:optimize, /docker:compose, /docker:security
- Python tools: dockerfile_analyzer.py (15 rules), compose_validator.py (best practices)
- References: dockerfile-best-practices.md, compose-patterns.md

Both skills include .claude-plugin/plugin.json and follow POWERFUL tier conventions.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

engineering/docker-development/.claude-plugin/plugin.json

@@ -0,0 +1,13 @@
+{
+  "name": "docker-development",
+  "description": "Docker and container development agent skill and plugin for Dockerfile optimization, docker-compose orchestration, multi-stage builds, and container security hardening. Covers build performance, layer caching, and production-ready container patterns.",
+  "version": "1.0.0",
+  "author": {
+    "name": "Alireza Rezvani",
+    "url": "https://alirezarezvani.com"
+  },
+  "homepage": "https://github.com/alirezarezvani/claude-skills/tree/main/engineering/docker-development",
+  "repository": "https://github.com/alirezarezvani/claude-skills",
+  "license": "MIT",
+  "skills": "./"
+}