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

pkg/hooks/worker.go

@@ -410,8 +410,6 @@ func findWorkerBinary() string {
 	locations := []string{
 		"./worker",
 		"./bin/worker",
-		filepath.Join(home, ".claude/plugins/cache/claude-mnemonic/claude-mnemonic/1.0.0/worker"),
-		filepath.Join(home, ".claude/plugins/marketplaces/claude-mnemonic/worker"),
 	}
 
 	for _, loc := range locations {
@@ -420,6 +418,19 @@ func findWorkerBinary() string {
 		}
 	}
 
+	// Try cache directory with any version (glob returns lexically sorted matches)
+	matches, _ := filepath.Glob(filepath.Join(home, ".claude/plugins/cache/claude-mnemonic/claude-mnemonic/*/worker"))
+	if len(matches) > 0 {
+		// Use the last match (latest version due to lexical sorting)
+		return matches[len(matches)-1]
+	}
+
+	// Try marketplaces directory
+	marketplacePath := filepath.Join(home, ".claude/plugins/marketplaces/claude-mnemonic/worker")
+	if _, err := os.Stat(marketplacePath); err == nil {
+		return marketplacePath
+	}
+
 	// Try PATH
 	if path, err := exec.LookPath("claude-mnemonic-worker"); err == nil {
 		return path