surface required MCP server semantics

Expose MCP server requiredness through config parsing, inventory reports, config hashes, and degraded startup failure context so orchestrators can distinguish optional degradation from required startup breakage.

Constraint: G007-plugin-mcp Task 3 requires required vs optional MCP behavior and must not mutate .omx/ultragoal.

Rejected: Treating all MCP failures as equivalent | it preserves the existing opacity that prevents required-server failures from being escalated differently.

Confidence: high

Scope-risk: moderate

Directive: Preserve required=false as the backward-compatible default; keep required surfaced in JSON/text inventory and degraded failure context when extending MCP lifecycle states.

Tested: cargo test -p runtime parses_typed_mcp_and_oauth_config -- --nocapture; cargo test -p runtime manager_discovery_report_keeps_healthy_servers_when_one_server_fails -- --nocapture; cargo test -p runtime manager_records_unsupported_non_stdio_servers_without_panicking -- --nocapture; cargo test -p commands renders_mcp_reports -- --nocapture; cargo check --workspace; cargo fmt --all -- --check

Not-tested: cargo clippy -p runtime -p commands -- -D warnings is blocked by pre-existing runtime/src/policy_engine.rs LaneContext clippy::struct_excessive_bools.

Co-authored-by: OmX <omx@oh-my-codex.dev>

rust/crates/runtime/src/mcp_stdio.rs

@@ -2726,7 +2726,7 @@ mod tests {
                 (
                     "broken".to_string(),
                     ScopedMcpServerConfig {
-                        required: false,
+                        required: true,
                         scope: ConfigSource::Local,
                         config: McpServerConfig::Stdio(McpStdioServerConfig {
                             command: broken_script_path.display().to_string(),