feat: add plan skill — comprehensive AARRR marketing plan generator

A new skill (`/plan {client-name}`) that produces an exhaustive 13-section
Notion-paste-ready marketing plan structured by AARRR (Acquisition,
Activation, Retention, Referral, Revenue), customized to the client's
current budget, team, stage, and tooling stack, mapped to future
funding-stage capability unlocks.

Three-phase workflow:
- INIT: research + structured 10-topic intake; pulls data from wired
  MCPs (Ahrefs, GA4, Stripe, Customer.io, etc.); offers to run
  /audit-marketing first
- REVIEW: section-by-section interactive draft with user confirmation
  on each of the 13 sections; resumable across sessions
- FINALIZE: compile, verification pass (cross-references, machine paths,
  brand voice), and optional publish to a shared GitHub repo

The 13 sections:
1. Executive summary
2. Strategic frame
3. Current state (scored against the 17-section audit-marketing rubric)
4. Acquisition
5. Activation
6. Retention
7. Referral
8. Revenue
9. 90-day roadmap (AARRR-tagged, owner-assigned)
10. 12-month outlook (with funding-stage milestones)
11. Marketing operations stack (skills + MCPs per AARRR stage)
12. Tactical idea bank (all 139 ideas from `marketing-ideas` mapped to
    AARRR + client-specific status: Now / Q2 / Q3+ / Q4+ / Skip)
13. Measurement, RACI, open decisions, appendix

References:
- methodology.md — full three-phase workflow
- plan-template.md — 13-section template with per-section guidance
- aarrr-framework.md — AARRR primer + diagnostic rules for which stage
  is the binding constraint
- current-state-rubric.md — 17-section audit-marketing rubric mapped
  to AARRR
- ops-stack-mapping.md — all 26+ marketing skills + MCP/API integrations
  mapped to AARRR stages
- idea-cross-reference.md — all 139 marketing-ideas mapped to AARRR
  with timing defaults
- funding-stage-unlocks.md — 5 standard funding tiers (pre-seed through
  Series B+) with budget profiles and capability unlocks
- measurement-framework.md — north-star patterns by business model,
  leading indicators by AARRR stage, review cadence
- client-types.md — variations by client archetype (B2B SaaS, D2C
  consumer app, hybrid hardware+software, marketplace, dev tool,
  deep-tech/clinical, commerce)
- example-olo.md — canonical reference plan from a real fCMO engagement

Updates:
- plugin.json + marketplace.json bumped to 2.3.0
- marketplace description updated to 43 skills
- VERSIONS.md entry added

Total skills: 43.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.claude-plugin/marketplace.json

@@ -6,13 +6,13 @@
   },
   "metadata": {
     "description": "Marketing skills for AI agents — conversion optimization, copywriting, SEO, paid ads, and growth",
-    "version": "2.2.0",
+    "version": "2.3.0",
     "repository": "https://github.com/coreyhaines31/marketingskills"
   },
   "plugins": [
     {
       "name": "marketing-skills",
-      "description": "42 marketing skills for technical marketers and founders: CRO, copywriting, cold email, prospecting, SEO, AI SEO, paid ads, SMS, ad creative, video production, image generation, co-marketing, churn prevention, pricing, referrals, revenue operations, sales enablement, customer research, site architecture, and more",
+      "description": "43 marketing skills for technical marketers and founders: CRO, copywriting, cold email, prospecting, SEO, AI SEO, paid ads, SMS, ad creative, video production, image generation, co-marketing, churn prevention, pricing, referrals, revenue operations, sales enablement, customer research, site architecture, comprehensive AARRR-structured marketing plans, and more",
       "source": "./"
     }
   ]

.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "marketing-skills",
   "description": "Marketing skills for AI agents — conversion optimization, copywriting, SEO, paid ads, ad creative, and growth",
-  "version": "2.2.0",
+  "version": "2.3.0",
   "author": {
     "name": "Corey Haines"
   },