CLI: streamline startup paths and env parsing

Add shared parseBooleanValue()/isTruthyEnvValue() and apply across CLI, gateway, memory, and live-test flags for consistent env handling.
Introduce route-first fast paths, lazy subcommand registration, and deferred plugin loading to reduce CLI startup overhead.
Centralize config validation via ensureConfigReady() and add config caching/deferred shell env fallback for fewer IO passes.
Harden logger initialization/imports and add focused tests for argv, boolean parsing, frontmatter, and CLI subcommands.

src/globals.ts

@@ -1,4 +1,4 @@
-import { getLogger, isFileLogLevelEnabled } from "./logging.js";
+import { getLogger, isFileLogLevelEnabled } from "./logging/logger.js";
 import { theme } from "./terminal/theme.js";
 
 let globalVerbose = false;