feat(utils): define file config (#13283)

** What
 - Allow auto-loaded Medusa files to export a config object.
 - Currently supports isDisabled to control loading.
 - new instance `FeatureFlag` exported by `@medusajs/framework/utils`
 - `feature-flags` is now a supported folder for medusa projects, modules, providers and plugins. They will be loaded and added to `FeatureFlag`

** Why
 - Enables conditional loading of routes, migrations, jobs, subscribers, workflows, and other files based on feature flags.

```ts
// /src/feature-flags

import { FlagSettings } from "@medusajs/framework/feature-flags"

const CustomFeatureFlag: FlagSettings = {
  key: "custom_feature",
  default_val: false,
  env_key: "FF_MY_CUSTOM_FEATURE",
  description: "Enable xyz",
}

export default CustomFeatureFlag
```

```ts
// /src/modules/my-custom-module/migration/Migration20250822135845.ts

import { FeatureFlag } from "@medusajs/framework/utils"

export class Migration20250822135845 extends Migration {
  override async up(){ }
  override async down(){ }
}

defineFileConfig({
  isDisabled: () => !FeatureFlag.isFeatureEnabled("custom_feature")
})
```

packages/cli/medusa-cli/src/reporter/index.ts

@@ -1,9 +1,9 @@
-import ora from "ora"
-import { ulid } from "ulid"
-import winston from "winston"
-import { inspect } from "util"
-import stackTrace from "stack-trace"
 import { track } from "@medusajs/telemetry"
+import ora from "ora"
+import stackTrace from "stack-trace"
+import { ulid } from "ulid"
+import { inspect } from "util"
+import winston from "winston"
 import { panicHandler } from "./panic-handler"
 
 const LOG_LEVEL = process.env.LOG_LEVEL || "http"
@@ -201,8 +201,9 @@ export class Reporter {
        * string values. Hence we will have to self convert
        * the error cause to a string
        */
-      if ("cause" in errorAsObject) {
-        toLog["cause"] = inspect(errorAsObject.cause)
+      const cause = (errorAsObject as any)?.cause
+      if (cause) {
+        toLog["cause"] = inspect(cause)
       }
     }