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/root.go

@@ -0,0 +1,44 @@
+package elog
+
+// The chat-logs root: where the tree lives, and whether logging is on at all.
+//
+// The state itself is in globals.go with the rest of the package-level variables;
+// this file holds only the accessors, because "is it on and where" is one question
+// with one answer and must not be asked in two pieces.
+
+// ChatLoggingEnabled reports whether chat logging is currently switched on.
+//
+// Exported so another package can assert the post-shutdown state instead of
+// inferring it from the absence of files.
+func ChatLoggingEnabled() (string, bool) {
+	return chatLogRoot()
+}
+
+// chatLogRoot returns the configured root and reports whether chat logging is
+// on, in a *single* read.
+//
+// The two must not be asked separately: a Close landing between an enabled()
+// check and a rootDir() read would leave the caller with an empty root, and
+// filepath.Join("", ...) silently yields a path relative to the working
+// directory — chat logs would be written wherever the supervisor happened to
+// start the process.
+func chatLogRoot() (string, bool) {
+	stateMu.RLock()
+	defer stateMu.RUnlock()
+
+	return root, root != ""
+}
+
+// setRoot switches chat logging on or off.
+func setRoot(dir string) {
+	stateMu.Lock()
+	defer stateMu.Unlock()
+
+	root = dir
+
+	if dir == "" {
+		failing = false
+	}
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */