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/config-guard.ts

@@ -0,0 +1,65 @@
+import {
+  isNixMode,
+  loadConfig,
+  migrateLegacyConfig,
+  readConfigFileSnapshot,
+  writeConfigFile,
+} from "../../config/config.js";
+import { danger } from "../../globals.js";
+import { autoMigrateLegacyState } from "../../infra/state-migrations.js";
+import type { RuntimeEnv } from "../../runtime.js";
+
+export async function ensureConfigReady(params: {
+  runtime: RuntimeEnv;
+  migrateState?: boolean;
+}): Promise<void> {
+  const snapshot = await readConfigFileSnapshot();
+  if (snapshot.legacyIssues.length > 0) {
+    if (isNixMode) {
+      params.runtime.error(
+        danger(
+          "Legacy config entries detected while running in Nix mode. Update your Nix config to the latest schema and retry.",
+        ),
+      );
+      params.runtime.exit(1);
+      return;
+    }
+    const migrated = migrateLegacyConfig(snapshot.parsed);
+    if (migrated.config) {
+      await writeConfigFile(migrated.config);
+      if (migrated.changes.length > 0) {
+        params.runtime.log(
+          `Migrated legacy config entries:\n${migrated.changes
+            .map((entry) => `- ${entry}`)
+            .join("\n")}`,
+        );
+      }
+    } else {
+      const issues = snapshot.legacyIssues
+        .map((issue) => `- ${issue.path}: ${issue.message}`)
+        .join("\n");
+      params.runtime.error(
+        danger(
+          `Legacy config entries detected. Run "clawdbot doctor" (or ask your agent) to migrate.\n${issues}`,
+        ),
+      );
+      params.runtime.exit(1);
+      return;
+    }
+  }
+
+  if (snapshot.exists && !snapshot.valid) {
+    params.runtime.error(`Config invalid at ${snapshot.path}.`);
+    for (const issue of snapshot.issues) {
+      params.runtime.error(`- ${issue.path || "<root>"}: ${issue.message}`);
+    }
+    params.runtime.error("Run `clawdbot doctor` to repair, then retry.");
+    params.runtime.exit(1);
+    return;
+  }
+
+  if (params.migrateState !== false) {
+    const cfg = loadConfig();
+    await autoMigrateLegacyState({ cfg });
+  }
+}