Add agent job execution via invoke_agent_step and ticker-echo test agent

[nicnocquee]

Summary

Implements execution of scheduled agent steps by enqueuing one invoke_agent_step job per expanded input set from check_schedules, and adds a minimal ticker-echo agent for local scheduler testing. The worker runs each job, calls the agent HTTP endpoint, and updates AgentJobExecution status (running / failed). Schedule executions get an enqueuing status and are linked to job executions via scheduleExecutionId.

Important changes

• hermes-worker: New invoke_agent_step job handler; invokes agent via HTTP, updates AgentJobExecution (running on start, failed on error). check_schedules now enqueues one invoke_agent_step per expanded input set via enqueueAgentJob callback.
• hermes-scheduler: executeSchedule accepts enqueueAgentJob; creates AgentJobExecution rows and enqueues payloads (jobId, executionId, scheduleExecutionId, endpoint, body, timeoutMs). Schedule execution status set to enqueuing while jobs are enqueued; final status (success/partial/failed) still derived from job outcomes.
• Database: AgentJobExecution gains scheduleExecutionId and relation to ScheduleExecution. ScheduleExecutionStatus gains enqueuing. Migration adds column and relation.
• ticker-echo agent: New app under apps/agents/ticker-echo; accepts tickerId input, logs it, returns success. Used for local testing with hermes-worker (env via @workspace/env agents-ticker-echo, README and tests included).

Other changes

• JobPayloadMap and job-payload-map include invoke_agent_step payload type.
• Hermes-worker and execute-schedule README/docs updated for new flow.
• Turbo config and env package updated for ticker-echo (build/tasks and env.agents.ticker-echo.example).

How to test

1. Apply migrations: pnpm db:migrate:dev (or equivalent) so schedule_execution_id and enqueuing exist.
2. Start ticker-echo: from repo root, pnpm --filter ticker-echo-agent dev. Use .env.local with ALLOW_ANY_BEARER_FOR_LOCAL=true and same bearer in hermes-worker’s AGENT_API_KEY.
3. In Hermes, register agent ticker-echo@1.0.0 with endpoint http://localhost:4010, create a pipeline with one step (ticker-echo, input e.g. { "tickerId": "{{tickerId}}" }), and create a schedule (or run pipeline once).
4. Run hermes-worker; when check_schedules runs, confirm invoke_agent_step jobs are enqueued and processed, ticker-echo logs show received tickerId, and AgentJobExecution rows move to running then completed (or failed on error).
5. Run full test suite: pnpm code-quality (including hermes-worker and hermes-scheduler and ticker-echo tests).