Handle Express Router imports after block comment banners

[rohitjavvadi]

Summary

This updates the Node route mapper so Express Router imports are detected when a block comment banner appears immediately before the import.

Example shape this now handles:

/* route imports */ import { Router as ApiRouter } from "express";

const router = ApiRouter();
router.get("/health", health);

Without this, routes created from the aliased router factory could be skipped during feature mapping.

The matcher stays conservative:

• non-Express imports are not treated as Express router factories
• fully commented-out Express imports are ignored
• multiline and stacked block comment banners are handled
• semicolon-prefixed same-line imports are handled

Validation

• Formatter check
• Lint
• Typecheck
• Build
• Mapper test suite
• Full test suite