release: v3.31.0 — Skills 2.0 taxonomy, evals, lifecycle

- §5.0 Two Kinds of Skills: Capability Uplift vs Encoded Preference
- §5.X Skill Lifecycle & Retirement: Catch Regressions + Spot Outgrowth
- §5.Y Skill Evals: Benchmark Mode, A/B Testing, Trigger Tuning
- Vitals + SE-CoVe community plugins documented (§8.5)
- Memory system: 3 corrections (Auto-Memories v2.1.59+, thresholds, WHAT/WHY/HOW)

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

machine-readable/reference.yaml

@@ -3,7 +3,7 @@
 # Source: guide/ultimate-guide.md
 # Purpose: Condensed index for LLMs to quickly answer user questions about Claude Code
 
-version: "3.30.2"
+version: "3.31.0"
 updated: "2026-03-03"
 
 # ════════════════════════════════════════════════════════════════
@@ -523,13 +523,29 @@ deep_dive:
     - "test-driven-development: 721 installs"
   skills_marketplace_status: "Community (Vercel Labs), launched Jan 21, 2026"
   skills_marketplace_changelog: "https://vercel.com/changelog/introducing-skills-the-open-agent-skills-ecosystem"
-  # Plugin System & Community Marketplaces (updated 2026-01-24)
-  plugins_system: 11048
-  plugins_commands: 11062
-  plugins_marketplace: 11100
-  plugins_community_marketplaces: 11358  # New section with ecosystem stats
+  # Plugin System & Community Marketplaces (updated 2026-03-06)
+  plugins_system: 12015
+  plugins_commands: 12029
+  plugins_marketplace: 12042
+  plugins_community_marketplaces: 12344
+  plugins_featured_community: 12385  # Vitals + SE-CoVe comparison section
   plugins_recommended: "examples/plugins/"
   plugins_se_cove: "examples/plugins/se-cove.md"
+  plugins_vitals:
+    url: "https://github.com/chopratejas/vitals"
+    install: "/plugin marketplace add chopratejas/vitals"
+    command: "/vitals:scan"
+    purpose: "Codebase hotspot detection — git churn x complexity x coupling centrality"
+    status: "v0.1 alpha"
+    updated: "2026-03-06"
+  plugins_se_cove_detail:
+    url: "https://github.com/vertti/se-cove-claude-plugin"
+    install: "/plugin marketplace add vertti/se-cove-claude-plugin"
+    command: "/chain-of-verification:verify"
+    purpose: "Chain-of-Verification — independent verifier prevents confirmation bias"
+    research: "arXiv:2309.11495 (ACL 2024)"
+    status: "v1.1.1 stable"
+    cost: "~2x tokens"
   plugins_official_docs: "https://code.claude.com/docs/en/plugins"
   plugins_official_reference: "https://code.claude.com/docs/en/plugins-reference"
   plugins_official_marketplaces: "https://code.claude.com/docs/en/plugin-marketplaces"
@@ -1446,7 +1462,7 @@ ecosystem:
       - "Cross-links modified → Update all 4 repos"
     history:
       - date: "2026-01-20"
-        event: "Code Landing sync v3.30.2, 66 templates, cross-links"
+        event: "Code Landing sync v3.31.0, 66 templates, cross-links"
         commit: "5b5ce62"
       - date: "2026-01-20"
         event: "Cowork Landing fix (paths, README, UI badges)"
@@ -1458,7 +1474,7 @@ ecosystem:
 onboarding_matrix_meta:
   version: "2.0.0"
   last_updated: "2026-02-05"
-  aligned_with_guide: "3.30.2"
+  aligned_with_guide: "3.31.0"
   changelog:
     - version: "2.0.0"
       date: "2026-02-05"
@@ -1486,7 +1502,7 @@ onboarding_matrix:
       core: [rules, sandbox_native_guide, commands]
       time_budget: "5 min"
       topics_max: 3
-      note: "SECURITY FIRST - sandbox before commands (v3.30.2 critical fix)"
+      note: "SECURITY FIRST - sandbox before commands (v3.31.0 critical fix)"
 
     beginner_15min:
       core: [rules, sandbox_native_guide, workflow, essential_commands]
@@ -1571,7 +1587,7 @@ onboarding_matrix:
         - default: agent_validation_checklist
       time_budget: "60 min"
       topics_max: 6
-      note: "Dual-instance pattern for quality workflows (v3.30.2)"
+      note: "Dual-instance pattern for quality workflows (v3.31.0)"
 
   learn_security:
     intermediate_30min:
@@ -1582,7 +1598,7 @@ onboarding_matrix:
         - default: permission_modes
       time_budget: "30 min"
       topics_max: 4
-      note: "NEW goal (v3.30.2) - Security-focused learning path"
+      note: "NEW goal (v3.31.0) - Security-focused learning path"
 
     power_60min:
       core: [sandbox_native_guide, mcp_secrets_management, security_hardening]
@@ -1607,7 +1623,7 @@ onboarding_matrix:
       core: [rules, sandbox_native_guide, workflow, essential_commands, context_management, plan_mode]
       time_budget: "60 min"
       topics_max: 6
-      note: "Security foundation + core workflow (v3.30.2 sandbox added)"
+      note: "Security foundation + core workflow (v3.31.0 sandbox added)"
 
     intermediate_120min:
       core: [plan_mode, agents, skills, config_hierarchy, git_mcp_guide, hooks, mcp_servers]