feat(engineering): integrate focused-fix skill — docs, command, agent, marketplace

- Normalize SKILL.md frontmatter to repo standard (remove non-standard
  license, metadata.* fields; inline description)
- Generate docs page (docs/skills/engineering/focused-fix.md)
- Add to mkdocs.yml nav (skills + commands)
- Create /focused-fix slash command (commands/ + .claude/commands/)
- Add to cs-senior-engineer agent (skill integration + new workflow #4)
- Update marketplace.json and plugin.json descriptions (30 → 31 skills)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

engineering/.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "engineering-advanced-skills",
-  "description": "30 advanced engineering skills: agent designer, agent workflow designer, AgentHub, RAG architect, database designer, migration architect, observability designer, dependency auditor, release manager, API reviewer, CI/CD pipeline builder, MCP server builder, skill security auditor, performance profiler, Helm chart builder, Terraform patterns, and more. Agent skill and plugin for Claude Code, Codex, Gemini CLI, Cursor, OpenClaw.",
+  "description": "31 advanced engineering skills: agent designer, agent workflow designer, AgentHub, RAG architect, database designer, migration architect, observability designer, dependency auditor, release manager, API reviewer, CI/CD pipeline builder, MCP server builder, skill security auditor, performance profiler, Helm chart builder, Terraform patterns, focused-fix, and more. Agent skill and plugin for Claude Code, Codex, Gemini CLI, Cursor, OpenClaw.",
   "version": "2.1.2",
   "author": {
     "name": "Alireza Rezvani",

engineering/focused-fix/SKILL.md

@@ -1,17 +1,6 @@
 ---
 name: "focused-fix"
-description: >
-  Use when the user asks to fix, debug, or make a specific feature/module/area work end-to-end.
-  Triggers: "make X work", "fix the Y feature", "the Z module is broken", "focus on [area]",
-  "this feature needs to work properly", "just make [feature] work". Not for quick single-bug fixes
-  (use systematic-debugging for that). This is for when an entire feature or module needs systematic
-  deep-dive repair across all its files and dependencies.
-license: MIT
-metadata:
-  version: 1.0.0
-  author: avinashchby
-  category: engineering
-  updated: 2026-03-22
+description: "Use when the user asks to fix, debug, or make a specific feature/module/area work end-to-end. Triggers: 'make X work', 'fix the Y feature', 'the Z module is broken', 'focus on [area]'. Not for quick single-bug fixes — this is for systematic deep-dive repair across all files and dependencies."
 ---
 
 # Focused Fix — Deep-Dive Feature Repair