Adds pass-rate to the CLI README's subcommand block. Updates CLAUDE.md
to note the new /pass-rate endpoint alongside the existing brain
HTTP REST API surface. Updates the session_log MCP tool's
final_status description to reflect the new pass|fail|skip vocabulary
introduced by Plan 5's SKILL.md instrumentation; the aggregator
still accepts legacy ok|error|skipped values for backwards compat.
986e3e1d12