feat(companion): emit release manifest metadata in bundles

docs/architecture/GATEWAY_SESSIONS_AND_QUEUE.md

@@ -21,7 +21,7 @@ If you only want the protocol surface, see `docs/api/PROTOCOL.md`.
 - Browser workflow reliability primitives (`browser.wait_for/assert/extract/checkpoint.*`) execute in the same queued session lane and apply browser-config guardrails (domain allowlist/high-risk confirmation, bounded retries, workflow step budget).
 - Companion `node.*` registration is per WebSocket connection; reconnects must re-register capabilities before invoking node RPC methods (or use runtime-client reconnect state replay to re-register/status/location/push automatically).
 - Companion packaging/bootstrap can be generated offline via `flynn companion --export-bootstrap <path|->`, which emits resolved gateway/node/runtime settings without opening a WebSocket session.
-- Companion release artifacts can be generated via `flynn companion --export-release-bundle <dir>`, producing bootstrap JSON + launcher + README + `CHECKSUMS.sha256` for installable shell distribution workflows.
+- Companion release artifacts can be generated via `flynn companion --export-release-bundle <dir>`, producing bootstrap JSON + launcher + README + `CHECKSUMS.sha256` + `RELEASE_MANIFEST.json` for installable shell distribution workflows.
 - Generated launchers validate `CHECKSUMS.sha256` before invoking `flynn companion`, reducing accidental tampered-bundle launches.
 - Companion release-bundle exports can optionally be signed (`--signing-key`, `--signing-key-id`) to emit `CHECKSUMS.sha256.sig` for distribution trust verification.
 - Companion release bundles can be verified before install via `flynn companion --verify-release-bundle <dir>` with optional signature-key checks.