chore: roadmap housekeeping and orientation rule

- Mark 0017, 0018 phase 1 and phase 2 HITL as complete in roadmap
- Add pre-0019 cleanup block: 0018 phase 3, write-eval refactor, eval updates
- Add orientation question rule to CONTEXT.md — read ROADMAP and open issue handoffs before answering "what's next?" questions
- Note close-out workflow gap in 0018 phase 3 grill questions

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

CONTEXT.md

@@ -56,6 +56,8 @@ All project state, decisions, context, and working conventions live in this repo
 
 Before answering any design or architecture question, check for existing decisions: `docs/adr/` (hard architectural decisions) and the resolved rows (marked ✅) in the `docs/ROADMAP.md` open questions table. Never propose an approach without verifying no decision already covers it.
 
+Before answering any orientation question ("what's next?", "where were we?", "what are we working on?", "what's the status?"), read `docs/ROADMAP.md` and check the handoff section of any open issue files in `docs/issues/` that are relevant to the current chunk. Do not answer from memory or git log alone — the roadmap and open issues are the authoritative source of current status.
+
 ### Working context
 This repo is built by a junior developer as a homelab tool intended to scale to professional environments. The agent should challenge ideas and reference industry standards rather than validate assumptions. Explain the why behind decisions — assume the user is learning, not just executing. Flag significant actions before taking them.