Fixes #14257.

Module rules assign module types to imported files — they are not include/exclude filters. Previously, when find_additional_modules walked the filesystem and discovered a file whose only matching rule had been shadowed by an earlier rule of the same type (via fallthrough: false, or by being a default rule overridden by a user-defined rule), wrangler would throw and fail the build.

For example, with this config and no_bundle: true, any .txt / .html / .sql file under the module root that did not match the user's glob would break the build, even when that file was never imported:

// wrangler.json
{
	"rules": [
		{
			"type": "Text",
			"globs": ["html/includeme.html"],
			"fallthrough": false
		}
	]
}

With this change, discovered files that only match a shadowed rule are silently skipped, and a debug-level log records each skip with a hint on how to include the file if desired (e.g. add fallthrough: true to the earlier rule or broaden the user rule's globs). The direct-import path in module-collection.ts is unchanged: importing a file in code that only matches a shadowed rule is still a hard error, since the imported file genuinely needs a defined module type.

Verified locally against the reporter's reproduction:

$ wrangler deploy --dry-run --outdir=dist
Attaching additional modules:
┌─────────────────────┬──────┬──────────┐
│ Name                │ Type │ Size     │
├─────────────────────┼──────┼──────────┤
│ html/includeme.html │ text │ 0.02 KiB │
├─────────────────────┼──────┼──────────┤
│ Total (1 module)    │      │ 0.02 KiB │
└─────────────────────┴──────┴──────────┘

• Tests
  • Tests included/updated
  • Automated tests not possible - manual testing has been completed as follows:
  • Additional testing not necessary because:
• Public documentation
  • Cloudflare docs PR(s):
  • Documentation not necessary because: the prior behavior was a bug — the public docs do not describe fallthrough: false as a way to filter out files, and the only user-visible difference is that a misleading error is no longer raised for unimported files.