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/memory-cli.test.ts

@@ -17,6 +17,10 @@ vi.mock("../agents/agent-scope.js", () => ({
   resolveDefaultAgentId,
 }));
 
+vi.mock("./program/config-guard.js", () => ({
+  ensureConfigReady: vi.fn(async () => {}),
+}));
+
 afterEach(async () => {
   vi.restoreAllMocks();
   getMemorySearchManager.mockReset();