refactor: adopt the .abcd/development namespace for developer docs (v0.7.1)

.abcd/README.md

@@ -0,0 +1,14 @@
+# .abcd/
+
+ferry's development namespace. Everything here is developer-facing material — it
+stays in the repo (transparent) but never ships to a ferry user. User-facing
+documentation lives under [`../docs/`](../docs/), which is the only dev-adjacent
+tree written for the reader of the CLI.
+
+- **[`development/`](development/)** — the durable record (committed): plans,
+  research, and architecture decisions. The specification the build works from.
+
+Working memory (`.work/`, committed shared orientation, and `.work.local/`,
+git-ignored local ephemera) currently sits at the repo root; a phase-2 migration
+folds it under this namespace (`.abcd/work/`, `.abcd/.work.local/`). Until then,
+see [`../AGENTS.md`](../AGENTS.md) for the working-memory split.

.abcd/development/README.md

@@ -0,0 +1,17 @@
+# Development record
+
+ferry's durable design record — the "what / why" the build works from. Kept in
+the repo (transparent) but developer-facing, never shipped to a ferry user;
+user-facing documentation lives under [`../../docs/`](../../docs/). Organised
+flat by artefact type, one canonical home per concept:
+
+| Folder | What it holds | Naming |
+|---|---|---|
+| [`plans/`](plans) | Dated design / implementation plans — "here's how we will build X". | `YYYY-MM-DD-topic.md` |
+| [`research/`](research) | Investigations that inform design without being decisions — SOTA surveys, spikes, prior-art reviews. | `YYYY-MM-DD-topic.md` |
+| [`decisions/`](decisions) | Architecture Decision Records (MADR) — settled decisions, the *why* plus rejected alternatives. | `NNNN-title.md` |
+
+**Conventions.** Plans and research notes are date-prefixed (chronological);
+ADRs use a sequential `NNNN` prefix (stable cross-reference handles). Present
+tense only — history lives in git. A decision extracted from a plan graduates to
+an ADR in [`decisions/`](decisions).

docs/decisions/0001-adr-naming-sequential-madr.md → .abcd/development/decisions/0001-adr-naming-sequential-madr.md

@@ -7,7 +7,8 @@
 
 ## Context and problem statement
 
-ferry records architecture decisions as MADR files under `docs/decisions/`. We
+ferry records architecture decisions as MADR files under
+`.abcd/development/decisions/`. We
 need one naming convention that sorts stably, reads unambiguously, and does not
 force coordination between branches before a decision can be written down. A
 superseded draft proposed a `<date>--<slug>` scheme (for example

.abcd/development/decisions/README.md

@@ -0,0 +1,11 @@
+# Decision records
+
+Architecture Decision Records (ADRs) in [MADR](https://adr.github.io/madr/)
+format — retrospective, settled decisions that record the *why* and the
+alternatives rejected.
+
+Each ADR is named `NNNN-title.md` with a sequential `NNNN` prefix (stable
+cross-reference handles, unlike the date-prefixed plans and research). Authors
+take the next free number optimistically on their branch; a collision blocks the
+merge so the second branch to land renumbers (see
+[ADR 0001](0001-adr-naming-sequential-madr.md)). Present tense only.

.abcd/development/plans/2026-07-08-v0.7.1.md

@@ -0,0 +1,45 @@
+# ferry v0.7.1 — developer documentation moves to the `.abcd/` namespace
+
+**Status:** shipped in v0.7.1 — the durable-record move and its tooling ripple
+are delivered.
+**Owner:** REPPL. **Type:** implementation plan (Diátaxis: one plan, no mixing).
+
+## 1. Goal and scope
+
+Align ferry with the sibling `abcd-cli` model so `docs/` carries user-facing
+documentation only and developer-facing records move to a `.abcd/development/`
+namespace. This is a structural migration — `git mv` plus text edits, no runtime
+behaviour change.
+
+In scope for v0.7.1 (the durable-record move and its ripple):
+
+- Move `docs/plans/`, `docs/research/`, and `docs/decisions/` (ADRs) to
+  `.abcd/development/{plans,research,decisions}/`.
+- Add structure READMEs: `.abcd/README.md`, `.abcd/development/README.md`, and
+  the per-directory READMEs, describing what each area holds and the naming
+  conventions (`YYYY-MM-DD-topic.md` for plans and research; `NNNN-title.md`
+  MADR for decisions).
+- Change the scaffold generator (`internal/agents/scaffold.go`) so a scaffolded
+  repo gets `docs/` = Diátaxis only and `.abcd/development/{plans,research,
+  decisions}` for developer records; regenerate the golden fixtures.
+- Repoint the release and consistency tooling (`scripts/check-plan-shipped.sh`,
+  `scripts/consistency-lint.sh`, `.github/workflows/release.yml`) and the docs
+  and agent text at the new paths.
+
+## 2. Out of scope (deferred)
+
+- Folding working memory (`.work/`, `.work.local/`) under the `.abcd/`
+  umbrella. That is an approved phase-2 migration handled separately.
+- Any cross-repo convention change to the shared `ABCDevelopment/CLAUDE.md`.
+
+## 3. Approach
+
+The proposal in
+[`.abcd/development/research/2026-07-08-docs-structure-proposal.md`](../research/2026-07-08-docs-structure-proposal.md)
+maps both repos and sets the ordered migration ripple. Because the release gate
+is tag-triggered on `main`, the moves and the tooling updates land in one change
+so `main` is always internally consistent. The scaffold golden tests fail loudly
+until their fixtures match the new layout — that lockstep is the safety net.
+
+The change is fully reversible: `git mv` plus text edits, no data migration and
+no release cutover.

docs/plans/README.md → .abcd/development/plans/README.md

@@ -1,6 +1,6 @@
 # Release plans
 
-Reference for the design plans under `docs/plans/`.
+Reference for the design plans under `.abcd/development/plans/`.
 
 Each plan captures the design for one release. A plan is named
 `YYYY-MM-DD-vX.Y.Z.md`, where the date is when the plan was written and the