feat(ros-z): move parameters behind async actor

[schmidma]

Summary

• moves bound ROS-Z parameters behind an async actor with a bounded mailbox
• changes parameter binding to node.bind_parameter_as::<T>(key).await? and updates node call sites
• routes remote parameter callbacks through actor commands with busy responses on mailbox backpressure or disconnect
• simplifies parameter actor lifecycle ownership by storing initialized resources directly instead of impossible None states
• narrows parameter actor internals so only Node::bind_parameter_as, NodeParameters, RemoteParameterClient, snapshots/errors, and the wire service/message types remain public API
• documents async binding semantics, failure modes, and one-binding-per-node behavior
• includes stale behavior_node parameter cleanup in etc/parameters/ros_z/base/behavior_node.json5 for parameters no longer consumed after the node migration

Related

• Fixes reiterate on node_parameter.rs #2510 by replacing the callback-time parameter mutation path with serialized async actor commands and explicit error propagation
• Builds on shared node FQN normalization and CLI FQN reuse from fix(ros-z): normalize node FQN formatting #2562, now merged into main

Test Plan

• cargo fmt --all -- --check
• ./pepsi fmt --check
• cargo clippy -p ros-z-protocol -p ros-z-cli -p ros-z --all-targets -- -D warnings
• ./pepsi clippy --locked . -- --deny warnings
• cargo nextest run -p ros-z-protocol -p ros-z-cli -p ros-z -E "test(fully_qualified_name_prefixes_bare_namespace) or test(fully_qualified_node_name_prefixes_bare_namespace) or test(remote_client_round_trips_and_receives_events) or test(local_mutation_reports_error_after_driver_task_aborts)"