web-client: the command outcome descriptor cannot carry a minted invite link or an accepted share

[FSM1]

What

CommandOutcomeDescriptor in packages/client/src/worker/protocol.ts carries done, queued and contactImported only. Two engine outcomes have no descriptor, so readOutcome in packages/client/src/worker/engineHost.ts refuses them with its unknown-kind error:

• inviteLinkMinted — landed with the invite mint arm, predates feat(engine): wire the rotation and grant facade command arms #1346.
• shareAccepted — landed with the accept arm in feat(engine): wire the rotation and grant facade command arms #1346.

Both cross the WASM boundary correctly (crates/wasm/src/lib.rs has the getters, and crates/wasm/src/host.rs covers the round-trip); it is only the TypeScript wrapper that cannot carry them. A web host can therefore issue createInviteLink and acceptShare but never read what they returned.

Acceptance

• CommandOutcomeDescriptor gains both variants, carrying the getters the wasm surface exposes: the invite secret, owner contact code, scope root name and bearer-write flag; and the accepted share's scope id, sequence, permission and newly-added flag.
• readOutcome maps both, using the same present() discipline the existing arms use so a getter the kind promises but does not answer is a refusal, not undefined.
• The unknown-kind refusal keeps its test — an outcome a future engine adds must still fail closed rather than resolve with a partial descriptor.
• packages/client's existing vitest suite covers both new arms.

Part of #635