docs: complete oq-promotion-sync — AGENTS.md current with Phase 1, add TN-12 tracker

- AGENTS.md architecture bullet: spec exists (present tense), OQ tracker
  authoritative; convention 16 de-hedged (shape pinned by ADR-004/005);
  alkcall version drift fixed (v0.4.x/v0.5.x -> v0.7.x per Cargo.toml);
  Phase 1-work bullet -> Phase 1 complete, Phase 2 in tasks/
- phase-0-findings.md: promotion note atop the Open Questions section
  pointing at docs/architecture/open-questions.md; convergence
  checklist's final item checked
- tasks: add architecture/oq-tn-12-tracker (external-trigger tracker for
  OQ-TN-12 deferred(scope), per sdd_process.md deferred-OQ two-halves
  rule); OQ-TN-12 Blocked-on text now references the tracker id
- tasks: oq-promotion-sync completed (scope grew: 3 folded stale
  AGENTS.md refs found during review + the TN-12 tracker)

Verified: taskgraph validate (13 tasks), grep sweep clean for stale
'not exist yet'/version-drift language, cargo test + cargo fmt --check

docs/research/phase-0-findings.md

@@ -290,6 +290,12 @@ referenced, tracked, and promoted into `docs/architecture/open-questions.md`
 in Phase 1. Half-answers and hunches are marked as such — the point of this
 document is to hold them without forcing premature decisions.
 
+> **Promoted 2026-09-07 (Phase 1):** OQ-TN-01..10 now live in
+> [`docs/architecture/open-questions.md`](../architecture/open-questions.md)
+> as OQ-TN-01..14 (statuses current as of the Phase 1 spec; OQ-TN-11..14
+> are the Phase 1 residues). The statuses below are the Phase 0 record and
+> are not maintained; treat the architecture tracker as authoritative.
+
 ### OQ-TN-01: Target addressing format
 
 What does the tunnel `params` on `channel/open` look like? alknet ADR-071
@@ -905,5 +911,7 @@ Candidate reading for the research specialist (to be expanded):
       adapter); "produce halves for a resource" is a function. The
       hub re-produce composition question is the only remaining
       OQ-TN-05 thread
-- [ ] Open questions promoted to Phase 1
-      `docs/architecture/open-questions.md` with statuses
+- [x] Open questions promoted to Phase 1
+      `docs/architecture/open-questions.md` with statuses — DONE
+      2026-09-07 (OQ-TN-01..10 promoted as OQ-TN-01..14, including the
+      Phase 1 residues; the convergence checklist is complete)