feat: v2.0.0 - Domain-based memory + multi-plugin marketplace structure

## Domain-based Memory (v2.0.0)
- Memory split into domains (backend, frontend, database, testing, deployment, global)
- Selective loading via `paths` frontmatter - only relevant memories load
- Automatic domain detection from file paths in conversation
- Auto-generated glob patterns when creating new domains
- Cross-domain analysis in /learn:reflect

## Repository Reorganization
- Restructured for multi-plugin marketplace: plugin/ → plugins/learn/
- Marketplace renamed: romfast-tools → romfast-plugins
- Repository to be renamed on Gitea: claude-learn → claude-plugins

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/learn/.claude-plugin/plugin.json

@@ -0,0 +1,8 @@
+{
+  "name": "learn",
+  "description": "Claude Learn: Session analysis for patterns and gotchas with domain-based memory",
+  "version": "2.0.0",
+  "author": {
+    "name": "Romfast Team"
+  }
+}