feat: unevalStream

[elliott-with-the-longest-name-on-github]

Adds unevalStream, a streaming version of uneval for values that contain promises. This is a much smaller alternative to #183, which had grown to ~3,450 lines plus ~9,500 lines of tests.

const { head, tail, id } = devalue.unevalStream(value, replacer, options); // synchronous

• head is an expression that recreates the value with every promise pending, no matter what has already settled, so the output is deterministic and doesn't depend on timing. Callers that want already-settled promises inlined can fold them in themselves with the replacer (js`Promise.resolve(${value})` ).
• tail is an async iterable of statement blocks that settle those promises as they settle on the server. A settled value can contain more promises, which later blocks settle.
• Object identity is preserved across head and every block, and the replacer is called at most once per object for the whole stream.
• Options: id (stable session key, for when heads need to be byte-identical), scope (where the client session table lives, globalThis.__d by default), signal and onerror.

It's built on the existing uneval emitter. The emitter gets a few internal hooks (enter, replace, reference, retain), so the stream can record where each object lives on the client during the emitter's own walk and refer to it by path in later blocks.

Tests are a table-driven round-trip harness. It checks every case across settlement orders, evaluating blocks separately vs. concatenated, identity, once-per-object replacer calls and session cleanup. On top of that are random-graph, UTF-8 transport and security regressions ported from #183.

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🦋 Changeset detected

Latest commit: f738f78

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
devalue	Minor

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