Payroll index consistency check workflow

[Wilfred007]

What

Payroll index consistency check workflow.

Why

There is no automated workflow verifying that the payroll index stays consistent with the query service's source data.

Scope

In scope:

• Define and implement the workflow steps described against payroll-indexing.service.ts
• Error handling and retry behavior for each step
• Observability (logging/tracing) for workflow execution
• Tests covering the happy path and at least one failure path

Out of scope:

• Redesigning the underlying service being orchestrated
• Building unrelated workflows not described in this issue
• New UI beyond what's needed to observe workflow status

Acceptance Criteria

• Workflow completes successfully on the happy-path fixture
• Workflow retries/handles at least one designed failure case
• Execution is observable via logs/traces
• Tests pass in CI

Technical Context

• Relevant files: payroll-indexing.service.ts, payroll-query.service.ts
• New surface area: this is part of the Mastra AI integration (greenfield) — coordinate with whichever foundation/infra issues (agent runtime bootstrap, tool registry, auth scoping) have landed so far