Fix/encrypted ipc transport

[MickeeJay]

feat: Wire encrypted stdio IPC transport into server entry point — closes #72

Summary

The encrypted transport logic was partially implemented but never wired into
the main server entry point. Configuration schemas were also missing the
necessary key fields, and several lint and config errors blocked the code
from building or running correctly in CI. This PR completes the integration,
making encrypted stdio IPC fully operational when a key is provided.

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Problem

Three gaps blocked the feature from being functional end-to-end:

• src/index.ts did not conditionally select the encrypted transport factory
  when a key was present — the implementation existed but was never invoked
• PULSAR_IPC_ENCRYPTION_KEY was absent from the configuration schema,
  so the key could not be read or validated at startup
• Lint errors in the transport layer and test suite (constant conditions,
  stale globals) prevented clean builds and reliable CI runs

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What Changed

1. Server entry point — encrypted transport wiring
Updated src/index.ts to use the encrypted transport factory when
PULSAR_IPC_ENCRYPTION_KEY is present, falling back to the standard
transport when no key is configured.

2. Configuration — PULSAR_IPC_ENCRYPTION_KEY
Added the key to the configuration schema with:

• Proper log redaction to prevent key material appearing in output
• Validation aligned with the transport layer's key requirements

3. Lint and config fixes
Refactored constant conditions and updated stale globals declarations in
the transport layer and test suite, restoring clean lint and typecheck passes.

**

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[adams813]

Nice Implementation, LGTM!