feat(011): delete custom execution plumbing + integration tests (WP03+WP04)

[AlexU-A]

Closes #29

Summary

This PR completes Feature 011 (Inngest Migration) — WP03 and WP04. WP01 (ported pipelines) and WP02 (replaced EventBus dispatch) are already on main.

WP03 — Delete custom execution plumbing (~5,013 LOC removed)

• Deleted: engine/, event-bus/, triggers/ directories, init.ts, benchmarks/step-latency.ts
• Deleted tests: tests/pipelines/engine/, event-bus/, triggers/
• Relocated types: ExecutionContext, PipelineStepHandler, StepHandlerRegistry moved from engine/step-runner.ts to pipelines/types.ts; 17 import sites updated
• src/index.ts: direct initialization replacing initializePipelineModule()
• pipeline-executor.ts: eventBus.publish() replaced with inngest.send()

WP04 — Integration tests (19 tests across 4 suites)

• corpus-update-pipeline: happy path, stub path, step output chaining, unique executionIds
• content-audit-pipeline: approval/rejection/timeout, 72h timeout assertion, concurrency config
• regulatory-change-monitor-pipeline: approval/rejection/timeout, 48h timeout (not 72h), source_query config
• concurrency: all event pipelines use event.data.tenantId; schedule-tick uses the CEL string literal

No live Inngest server required — tests invoke the function internal fn handler with mocked step objects.

Acceptance gate (T018)

• tsc --noEmit: 0 errors
• vitest run: 280/280 passing
• Net deletion: 5,013 LOC removed
• No engine/, event-bus/, triggers/ in src/pipelines/
• Zero dangling imports to deleted modules

Reviewer checklist

• src/pipelines/ no longer contains engine/, event-bus/, or triggers/
• src/pipelines/types.ts exports ExecutionContext, PipelineStepHandler, StepHandlerRegistry
• src/index.ts initializes directly (no initializePipelineModule)
• pipeline-executor.ts uses inngest.send() not eventBus.publish()
• Integration tests cover reject AND timeout branches (not just approval)
• content-audit timeout is 72h, regulatory-change-monitor timeout is 48h
• schedule-tick concurrency key includes inner quotes: '"schedule-tick-global"'

Generated with Claude Code

[grndlvl]

Review note: pipeline/manual.triggered has no Inngest handler

While reviewing the pipeline framework findings from PR #28 (grndlvl's review), I audited this PR and found that the manual trigger route sends inngest.send({ name: 'pipeline/manual.triggered', ... }) and the test verifies the send — but no Inngest function is registered to handle this event. It's a dead letter.

Either:

• Add a function in src/inngest/functions/ that listens for { event: 'pipeline/manual.triggered' } and executes the pipeline, or
• Revert the route to use a different dispatch mechanism

[AlexU-A]

Fixed in 69eb3b5 — added createManualTriggerPipeline Inngest function that handles pipeline/manual.triggered events. Follows the same factory pattern as corpus-update and content-audit pipelines: per-tenant concurrency, two-step execution (source-query, content-generation), stub fallback for unregistered handlers. Registered in allFunctions array. Typecheck passes.