Global code ovehaul - remove CAS and other, add 15 minute greet check

- Remove CAS, as it no longer works for us
- Remove other checks
- Implement 15 minute greet timeout check
- Fix chat logos
- Ditch thirdparty logger, use stdlib log facility wrapper for logging

internal/elog/init.go

@@ -0,0 +1,46 @@
+package elog
+
+import (
+	"fmt"
+	"os"
+)
+
+// Init switches chat logging on.
+//
+// An empty root disables it, and every Log* call becomes a no-op — chat logging
+// is optional. A non-empty root must already exist: a path that does not is a
+// typo, and silently logging nowhere is the worst possible response to one, so
+// this returns an error and moon.ParseConfig treats it as fatal.
+func Init(rootDir string) error {
+	if rootDir == "" {
+		setRoot("")
+
+		return nil
+	}
+
+	info, err := os.Stat(rootDir)
+	if err != nil {
+		return fmt.Errorf("chat_logs directory %s is not usable: %w", rootDir, err)
+	}
+
+	if !info.IsDir() {
+		return fmt.Errorf("%w: %s", errNotDirectory, rootDir)
+	}
+
+	setRoot(rootDir)
+
+	return nil
+}
+
+// Close disables chat logging.
+//
+// Nothing is held open between lines, so there are no handles to close; this
+// exists so shutdown has a symmetric counterpart to Init and so a misbehaving
+// caller can stop writing.
+func Close() error {
+	setRoot("")
+
+	return nil
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */