fix: prevent internal prompts and duplicates in memory database

- Add server-side detection of SDK processor's internal system prompt
  in handleSessionInit, since CLAUDE_MNEMONIC_INTERNAL env var is not
  propagated by Claude Code to hook subprocesses
- Add cross-session duplicate detection (FindRecentPromptByTextGlobal)
  to catch same prompt text arriving from different session IDs
- Add hooks, mcpServers, and commands references to plugin.json per
  Claude Code plugin spec
- Remove MCP server injection from register-plugin.sh (now in plugin.json)
- Use ${CLAUDE_PLUGIN_ROOT} for statusline path instead of hardcoded path
- Add python3 fallback for plugin registration when jq is unavailable
- Replace hardcoded 1.0.0 version in findWorkerBinary with glob lookup
- Add cache copy verification in register-plugin.sh
- Add update-version Makefile target to keep metadata in sync

plugin/.claude-plugin/plugin.json.tpl

@@ -5,5 +5,14 @@
   "author": {
     "name": "lukaszraczylo",
     "email": "lukaszraczylo@users.noreply.github.com"
-  }
+  },
+  "hooks": "./hooks/hooks.json",
+  "mcpServers": {
+    "claude-mnemonic": {
+      "command": "${CLAUDE_PLUGIN_ROOT}/mcp-server",
+      "args": ["--project", "${CLAUDE_PROJECT}"],
+      "env": {}
+    }
+  },
+  "commands": ["./commands/restart.md"]
 }