fix(jupyter): support IPC connection files

[quillaid]

Summary

• Support Jupyter connection files that set transport to ipc.
• Bind Deno Jupyter kernel sockets as Unix sockets using the Jupyter IPC <ip>-<port> convention.
• Update the integration-test client to accept complete ipc://... endpoints and add Unix-only IPC coverage for heartbeat and kernel_info_reply.

Validation

• ./tools/format.js cli/js/jupyter_kernel.js tests/integration/jupyter_client.rs tests/integration/jupyter_tests.rs passed before the host cleanup.
• git diff --check passed.
• Full local integration validation was not completed. Building target/debug/deno for the targeted integration test was stopped because host disk pressure dropped free space below 8G while Deno target/ grew large. No further local Deno build/test was run after cleanup.

Closes #35201

Disclosure: this PR was AI-assisted.

[deno-cla-assistant]

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