refactor(plugin): split research skills into separate plugin

New plugin: claude/research (core-research v0.1.0)
- 12 collection/research skills moved from core
- collection subsystem (hooks, scripts) moved
- Installed separately when research work is needed

Core plugin bumped to v0.12.0 — now focused on:
- Dispatch, review, messaging, OpenBrain (operational)
- Deploy, app-split, repo-sweep (infrastructure)
- Architecture review, security review (quality)

Marketplace updated with CoreResearch entry.

Co-Authored-By: Virgil <virgil@lethean.io>

.claude-plugin/marketplace.json

@@ -9,8 +9,14 @@
     {
       "name": "CoreAgent",
       "source": "./claude/core",
-      "description": "Core agent platform",
-      "version": "0.11.0"
+      "description": "Core agent platform — dispatch, review, messaging, OpenBrain",
+      "version": "0.12.0"
+    },
+    {
+      "name": "CoreResearch",
+      "source": "./claude/research",
+      "description": "Blockchain archaeology, whitepaper archival, community history, market data collection",
+      "version": "0.1.0"
     },
     {
       "name": "CorePHP",

claude/core/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "CoreAgent",
   "description": "Core agent platform — dispatch (local + remote), verify+merge, CodeRabbit/Codex review queue, GitHub mirror, cross-agent messaging, OpenBrain integration, inbox notifications",
-  "version": "0.11.0",
+  "version": "0.12.0",
   "author": {
     "name": "Lethean Community",
     "email": "hello@lethean.io"

claude/research/.claude-plugin/plugin.json

@@ -0,0 +1,20 @@
+{
+  "name": "core-research",
+  "description": "Data collection and research skills for the Lethean Network — blockchain archaeology, whitepaper archival, community history, and market data collection",
+  "version": "0.1.0",
+  "author": {
+    "name": "Lethean Community",
+    "email": "hello@lethean.io"
+  },
+  "homepage": "https://dappco.re/agent/claude",
+  "repository": "https://github.com/dAppCore/agent.git",
+  "license": "EUPL-1.2",
+  "keywords": [
+    "research",
+    "collection",
+    "blockchain",
+    "archaeology",
+    "whitepapers",
+    "archival"
+  ]
+}