#21612: feat(gateway): add ops runtime summary API

## Summary - add a read-only gateway method `ops.runtime.summary` to aggregate runtime status for cron/jobs, sessions, and subagents - include basic filters: `activeMinutes`, `limit`, `search`, `fromMs`, `toMs`, `includeDisabledCron` - wire the method into gateway method registry and read scope - add unit tests for response aggregation and params validation ## Why Mission Control needs one endpoint to answer quickly: what is running, what is failing, and what needs manual action. ## API Method: `ops.runtime.summary` Response includes: - `summary.cron/sessions/subagents` - `cron[]` - `sessions[]` - `subagents[]` ## Validation - `pnpm vitest src/gateway/server-methods/ops-runtime.test.ts src/gateway/method-scopes.test.ts` - `pnpm exec oxlint --type-aware src/gateway/server-methods/ops-runtime.ts src/gateway/server-methods/ops-runtime.test.ts src/gateway/server-methods.ts src/gateway/server-methods-list.ts src/gateway/method-scopes.ts` - `pnpm exec oxfmt --check src/gateway/server-methods.ts src/gateway/server-methods/ops-runtime.test.ts src/gateway/server-methods/ops-runtime.ts src/gateway/server-methods-list.ts src/gateway/method-scopes.ts` Related: #21600 <!-- greptile_comment --> <h3>Greptile Summary</h3> Added a new read-only gateway method `ops.runtime.summary` that aggregates runtime status for cron jobs, sessions, and subagents into a single endpoint. The implementation includes proper parameter validation, filtering (activeMinutes, limit, search, time range), and comprehensive unit tests. <h3>Confidence Score: 5/5</h3> - This PR is safe to merge with minimal risk - The implementation is clean, well-tested, and follows established patterns in the codebase. Parameter validation is thorough, the method is properly scoped as read-only, integration points are correctly wired, and unit tests cover both success and error cases. - No files require special attention _{Last reviewed commit: 3733ef0} <!-- greptile_other_comments_section --> _{(3/5) Reply to the agent's comments like "Can you suggest a fix for this @greptileai?" or ask follow-up questions!} <!-- /greptile_comment -->