docs: record v1 detective epic and remaining gaps.

Read path and MCP are in; write, hops, corpus, and CI eval are still open. Board is Gitea epic #16.

docs/README.md

@@ -5,6 +5,7 @@ related:
   - docs/runbook.md
   - docs/design.md
   - PLAN.md
+  - docs/roadmap.md
 ---
 
 # 2dph docs (Diataxis)
@@ -16,6 +17,7 @@ Evidence-first knowledge graph. Facts need proof or they are
 |------|-----|
 | tutorial / howto | [runbook](runbook.md) — run anywhere (uv, Go, Docker) |
 | explanation | [design](design.md) — two roots, deduction, D17/D20/D18 |
+| explanation | [roadmap](roadmap.md) — gap to v1 (epic #16) |
 | howto | [picoclaw](picoclaw.md) — MCP agent profile |
 | howto | [reasoner](reasoner.md) — CPU bake-off (D18) |
 | reference | [PLAN.md](../PLAN.md) — decisions D1–D21 |
@@ -26,9 +28,11 @@ Python write sidecar, **D14** `bin/{subject}/{method}.go`, **D15** Gitea origin,
 
 Search: `bin/brain/search.go "query"` (HTTP: `bin/brain/serve.go` —
 `/health` `/search` `/get` `/stats` `/audit` `/ingest`). `--hop` is
-not a walk; the flag errors until File/FROM_FILE edges exist.
+not a walk; the flag errors. Schema has `FROM_FILE`; search does not
+use it ([#17](https://git.produktor.io/eSlider/2dph/issues/17)).
 
-Work board: [Gitea issues](https://git.produktor.io/eSlider/2dph/issues).
+Work board: [Gitea issues](https://git.produktor.io/eSlider/2dph/issues)
+([epic #16](https://git.produktor.io/eSlider/2dph/issues/16)).
 PRs and CI: GitHub [`eSlider/2dph`](https://github.com/eSlider/2dph).
 
 Published docs live here and match live commands.