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/cli/program/helpers.ts

@@ -16,3 +16,9 @@ export function parsePositiveIntOrUndefined(value: unknown): number | undefined
   }
   return undefined;
 }
+
+export function resolveActionArgs(actionCommand?: import("commander").Command): string[] {
+  if (!actionCommand) return [];
+  const args = (actionCommand as import("commander").Command & { args?: string[] }).args;
+  return Array.isArray(args) ? args : [];
+}