MCP tools can now be 'adopted' as passthrough tools instead of routed through the device bridge

What

• A reworked remote-tools setup pipeline, gated by adoptMcpOverChannelSwitchOn, computes a machineMcpToolsPolicy (allowed/denied/pending/unavailable) for each MCP server and decides whether its tools are "adopted" as passthrough tools, used directly by a remote worker, instead of being routed through the device bridge. Adoption requires remote tool forwarding to be enabled, the channel switch to be on, policy to allow it, and the tool not to be disabled.
• The remote-tools announce handler now computes passthrough_adopted and passthrough_declined (with reasons policy, pending, or unavailable) outcomes and reports them in telemetry.
• The remote_tools_announce acknowledgement schema was extended with passthrough_adopted (count of MCP tools kept) and passthrough_declined fields, and ignored_tools now documents more reasons, including tools beyond the cap that the worker keeps.

Why Routing every MCP tool call through the device bridge adds overhead; letting a remote worker adopt and call MCP tools directly, when policy allows, should make those calls faster while keeping visibility into which tools were adopted versus declined and why.