Decide the fate of POST /api/ai — it returns 501 while the pipeline it describes exists

apps/web/src/app/api/ai/route.ts:22 authenticates the caller, reads the body, then returns 501:

    // TODO: Wire up the AI pipeline
    // 1. Search Pathfinder for relevant docs
    // 2. Generate response with Claude
    // 3. Return structured response with confidence
    return NextResponse.json({ message: 'AI pipeline not yet implemented', ... }, { status: 501 });

The pipeline it describes exists and is production-tested — packages/outpost/ai/src/pipeline.ts, used by the AI_RESPONSE handler.

Decision needed

Either wire the route to the real pipeline (it would give the dashboard a "draft an answer for this" affordance and a way to exercise the pipeline without waiting for inbound traffic), or delete the route. A permanently-501 endpoint that looks implemented is worse than no endpoint.

If we wire it: it must inherit the groundedness gate (#143) and SHADOW_MODE handling like every other consumer, not call the generator directly.

Start with apps/web/src/app/api/ai/route.ts:22 and compare its 501 response with packages/outpost/ai/src/pipeline.ts and the AI_RESPONSE handler. Determine whether the route should be removed or connected through the existing pipeline, including groundedness gate #143 and SHADOW_MODE handling; done means no misleading permanent 501 endpoint remains.