Add buzz_agent_mcp_servers to RuntimeConfigSurface, populated by
resolve_config_surface via the existing effective_buzz_agent_mcp_servers
merge (global < definition < agent, enabled-only) for the buzz-agent
runtime only. Every other runtime keeps the field empty and continues
to surface its servers via extensions.
This is the WYSIWYG read path the PR3 UI's read-only buzzAgentSlot will
consume — the effective list is now reachable from the config-bridge
surface the frontend already reads, matching what actually runs at
spawn (spawn_hash.rs, runtime.rs) rather than just the agent's own
record layer.
Also bumps two pre-existing file-size overrides (agent_config.rs,
readiness.rs) to their gate's own split-count, matching this diff and
a prior unaccounted +1 line already on the branch.
Co-authored-by: Will Pfleger <pfleger.will@gmail.com>
Signed-off-by: Will Pfleger <pfleger.will@gmail.com>