Fix DWDS injected client loading when running webdev in AOT mode

[Varadraj75]

This PR fixes an issue where the DWDS injected debugging client fails to load when webdev is installed and run in AOT mode (for example via dart pub global activate).

In AOT snapshots, resolving the injected client using Isolate.resolvePackageUri can fail, leading to the runtime error:
Bad state: Cannot resolve "package:dwds/src/injected/client.js"

To address this, the injected DWDS client is now served using an AOT-safe approach, avoiding runtime package URI resolution and ensuring the client is always available when serving .bootstrap.js entrypoints.

This restores correct debugging behavior for globally activated webdev without affecting existing JIT or development workflows.
closes #2761

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[Varadraj75]

Hey @nshahan, could you please review this PR when you get a chance?
Happy to make any changes or adjustments if needed—thanks!