docs(changelog): record that remote control attaches again [skip ci]

Platform 932b873e/c231a299 replaced the retired 0.9.13 runtime identity
pin, which refused every 0.10.x Engine's `codewhale rc` with
runner_runtime_identity_unavailable. The pin is exact: the 0.10.3 release
must bump Platform's CWC_CODEWHALE_RUNTIME_VERSION (and its provider
export) to 0.10.3 and deploy it with the release commit/image/digest, or
0.10.3 remote control is refused again. Tracked on CW-7525.

Verified: scripts/sync-changelog.sh --check passes. Production rc proof
pending the founder's deploy.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- **Remote control works again:** `codewhale rc` (`/rc`) can attach to the hosted control plane for web Chat again. The control plane had only accepted the retired 0.9.13 runtime identity, so every 0.10.x Engine was refused with `runner_runtime_identity_unavailable`; it now accepts the exact released runtime identity (commit, image and digest) and fails closed when they are not configured.
 - **Modern MCP client:** MCP servers now connect through the official MCP SDK (2.4) behind Codewhale's Rust broker by default (`mcp_backend = "host"`; `"rust"` stays available for one release). Servers that speak the 2026-07-28 revision are discovered with `server/discover`; other stdio and HTTP servers fall back to the legacy `initialize` handshake, and configured SSE servers keep theirs. Rust keeps process, network, credential, catalog, approval and cancellation authority. (CW-6713)
 - **MCP compatibility fixes:** older servers that answer the discovery probe with an error or an unrelated result now connect through the legacy handshake instead of being refused after the probe. A server that rejects sign-in reports its real 401 and the `/mcp login` hint rather than the probe's "method not found". A stale OAuth token is refreshed once when the probe itself is rejected. A server whose command cannot start now says why (for example, command not found) instead of a generic broker refusal.
 - **DeepSeek Harness plugins:** reviewed DSH plugins (definition API pinned to DSH 0.2.1-rc.2 in a shared compatibility table) run in the Native extension host. Tool output is validated against its declared schema, unsupported options are refused instead of ignored, and plugin commands can submit a prompt with visible plugin attribution. Terminal command receipts are kept in thread snapshots without entering model history. Changing the compatibility table invalidates earlier trust. Plugin UI views remain disabled. (CW-7054)

crates/tui/CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+- **Remote control works again:** `codewhale rc` (`/rc`) can attach to the hosted control plane for web Chat again. The control plane had only accepted the retired 0.9.13 runtime identity, so every 0.10.x Engine was refused with `runner_runtime_identity_unavailable`; it now accepts the exact released runtime identity (commit, image and digest) and fails closed when they are not configured.
 - **Modern MCP client:** MCP servers now connect through the official MCP SDK (2.4) behind Codewhale's Rust broker by default (`mcp_backend = "host"`; `"rust"` stays available for one release). Servers that speak the 2026-07-28 revision are discovered with `server/discover`; other stdio and HTTP servers fall back to the legacy `initialize` handshake, and configured SSE servers keep theirs. Rust keeps process, network, credential, catalog, approval and cancellation authority. (CW-6713)
 - **MCP compatibility fixes:** older servers that answer the discovery probe with an error or an unrelated result now connect through the legacy handshake instead of being refused after the probe. A server that rejects sign-in reports its real 401 and the `/mcp login` hint rather than the probe's "method not found". A stale OAuth token is refreshed once when the probe itself is rejected. A server whose command cannot start now says why (for example, command not found) instead of a generic broker refusal.
 - **DeepSeek Harness plugins:** reviewed DSH plugins (definition API pinned to DSH 0.2.1-rc.2 in a shared compatibility table) run in the Native extension host. Tool output is validated against its declared schema, unsupported options are refused instead of ignored, and plugin commands can submit a prompt with visible plugin attribution. Terminal command receipts are kept in thread snapshots without entering model history. Changing the compatibility table invalidates earlier trust. Plugin UI views remain disabled. (CW-7054)