feat(kernel-utils): add sheaf programming module

packages/sheaves/CHANGELOG.md

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+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [Unreleased]
+
+## [0.1.0]
+
+### Added
+
+- Initial release, extracted from `@metamask/kernel-utils`.
+- `sheafify({ name, providers })` — constructs a sheaf authority manager over a
+  set of capability providers.
+- `Provider<M>` type — an input to `sheafify`: a `{ handler, metadata? }` pair
+  where `handler` is an exo and `metadata` is an optional `MetadataSpec<M>`.
+- `Candidate<M>` type — a post-evaluation entry in the stalk: `{ handler,
+metadata }` with metadata already resolved from its spec.
+- `Handler` type — an exo capability covering a region of the interface
+  topology.
+- `Policy<M>` type — an `async function*` coroutine that receives candidates
+  and yields them in preference order; drives the sheaf dispatch loop.
+- `PolicyContext<M>` type — context passed to the policy: `{ method, args,
+constraints }`.
+- `MetadataSpec<M>` discriminated union with three variants: `constant`,
+  `source`, and `callable`.
+- `constant(value)` — static metadata spec; value is fixed at construction.
+- `source(src)` — source-string metadata spec; compiled via the optional
+  compartment at `sheafify` construction time.
+- `callable(fn)` — callable metadata spec; evaluated per-dispatch with the
+  invocation arguments.
+- `makeHandler(name, guard, methods)` — creates a named, guarded exo handler.
+- `makeRemoteSection(tag, remoteRef, metadata?)` — builds a provider that
+  wraps a remote capability, fetching its interface guard via `E`.
+- `noopPolicy` — a policy that yields candidates in the order received.
+- `proxyPolicy(gen)` — wraps an existing generator to satisfy the `Policy`
+  call signature.
+- `withFilter(predicate)` — higher-order policy combinator that pre-filters
+  the candidate list before passing it to the inner policy.
+- `withRanking(comparator)` — higher-order policy combinator that pre-sorts
+  the candidate list before passing it to the inner policy.
+- `fallthrough(policyA, policyB)` — composes two policies so that `policyB`
+  is tried only after `policyA` is exhausted.
+- `Sheaf<M>` type — the authority manager returned by `sheafify`; exposes
+  `getSection`, `getDiscoverableSection`, `getGlobalSection`, and
+  `getDiscoverableGlobalSection`.
+- `documents/POLICY.md` — documents the policy coroutine protocol,
+  `PolicyContext`, and the semantic equivalence assumption.
+- `documents/USAGE.md` — annotated usage examples.
+
+[Unreleased]: https://github.com/MetaMask/ocap-kernel/compare/@metamask/sheaves@0.1.0...HEAD
+[0.1.0]: https://github.com/MetaMask/ocap-kernel/releases/tag/@metamask/sheaves@0.1.0

packages/sheaves/LICENSE.APACHE2

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packages/sheaves/LICENSE.MIT

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