fix: Correct hooks format - add nested hooks array

SessionEnd hooks require { hooks: [...] } format, not direct type/command.
Fixed install-hooks.sh script and setup.md command.
Bump version to 2.1.3

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

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

@@ -1,7 +1,7 @@
 {
   "name": "learn",
   "description": "Claude Learn: Session analysis for patterns and gotchas with domain-based memory, selective saving, and memory hygiene",
-  "version": "2.1.2",
+  "version": "2.1.3",
   "author": {
     "name": "Romfast Team"
   }