feat(deep-research): V6.1 source accessibility policy and Counter-Review Team

- Correct source accessibility: distinguish circular verification (forbidden)
  from exclusive information advantage (encouraged)
- Add Counter-Review Team with 5 specialized agents (claim-validator,
  source-diversity-checker, recency-validator, contradiction-finder,
  counter-review-coordinator)
- Add Enterprise Research Mode: 6-dimension data collection framework
  with SWOT, competitive barrier, and risk matrix analysis
- Update version to 2.4.0
- Add comprehensive reference docs:
  - source_accessibility_policy.md
  - V6_1_improvements.md
  - counter_review_team_guide.md
  - enterprise_analysis_frameworks.md
  - enterprise_quality_checklist.md
  - enterprise_research_methodology.md
  - quality_gates.md
  - report_template_v6.md
  - research_notes_format.md
  - subagent_prompt.md

Based on "深度推理" case study methodology lessons learned.

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

.claude-plugin/marketplace.json

@@ -693,10 +693,10 @@
     },
     {
       "name": "deep-research",
-      "description": "Generate format-controlled research reports with evidence tracking, citations, and iterative review. Use when users request research reports, literature reviews, market or industry analysis, competitive landscapes, policy or technical briefs, or strict report templates and section formatting",
+      "description": "Generate format-controlled research reports with evidence tracking, source governance, and multi-pass synthesis. V6.1 adds: source accessibility (circular verification forbidden, exclusive advantage encouraged). Enterprise Research Mode: six-dimension data collection, SWOT/barrier/risk frameworks, and three-level quality control for company research",
       "source": "./",
       "strict": false,
-      "version": "1.0.0",
+      "version": "2.4.0",
       "category": "documentation",
       "keywords": [
         "research",
@@ -706,7 +706,10 @@
         "market-research",
         "citations",
         "evidence",
-        "deepresearch"
+        "deepresearch",
+        "enterprise",
+        "company-research",
+        "due-diligence"
       ],
       "skills": [
         "./deep-research"