docs: adopt workspace-wide agent standards and retire sow-docs

Scaffold the per-repo configuration the engineering skills expect, and put
the three-way split of work into standing law:

- Live work -> wayfinder maps + Gitea issues (closeable, assignable,
  queryable).
- Settled decisions -> ADR files in docs/adr/ (immutable, findable, never
  closed).
- Standing law -> DOCTRINE.md / AGENTS.md / CONTEXT.md.

Adds docs/agents/{issue-tracker,triage-labels,domain}.md and an
"Agent skills" section in AGENTS.md. The tracker doc records Gitea via the
tea CLI, the wayfinder map/ticket/blocking operations, and the rule that
issues follow ownership: file work in the repo that owns it, not the one you
happen to be standing in.

ADR-0001 (markdown is reference, law, or an ADR - nothing else) is adopted
from sow-codebase so the rule is local to every repo.

sow-docs is retired: its 35 decisions become ADRs in the repos that own them,
its living docs move to sow-platform and sow-assets-manifest, and its
unfinished intent becomes Gitea issues.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

docs/adr/0001-markdown-is-reference-or-law-only.md

@@ -0,0 +1,55 @@
+# ADR-0001: Markdown in this repo is reference, law, or an ADR — nothing else
+
+- **Status:** Accepted
+- **Date:** 2026-07-24
+- **Origin:** Adopted workspace-wide from `sow-codebase` ADR-0001, which records
+  the full context (a `docs/` tree that had grown to 434 files, ~27MB, most of
+  it dead process artifacts). This repo adopts the same law so the rule is
+  local, not a cross-repo reference.
+
+## Context
+
+Markdown that *claims to describe current state or a plan* rots, because
+reality diverges and nobody edits the file. Markdown that claims neither — a
+dated, immutable decision record, or a standing rule — does not rot.
+
+Two different things get conflated:
+
+- **Rationale** — why a system is shaped the way it is. Worth keeping.
+- **Process artifacts** — plans, specs, concepts, handoffs, trackers. A record
+  of how work happened, not what is true now.
+
+Left unchecked, every completed effort leaves its planning behind and the repo
+accumulates a "historical" pile that agents and humans must route around to
+find the few live docs.
+
+## Decision
+
+Markdown may exist in this repo only as one of three genres:
+
+1. **Current-state reference** — describes what the code does now, kept honest
+   by code review touching it.
+2. **Standing law** — `DOCTRINE.md`, root and folder-scoped `AGENTS.md`,
+   `CONTEXT.md`. States rules and vocabulary, not plans.
+3. **Immutable decision record** — ADRs under `docs/adr/`. Append-only; never
+   edited, only superseded by a later ADR that points back.
+
+Anything else — implementation plans, design specs, concepts, handoffs,
+progress trackers, scratch — is **process** and does not live in the repo. It
+lives in Gitea issues and wayfinder maps, where it can be assigned, closed, and
+superseded. Small tasks need no written plan at all.
+
+Deleting a process document is not destroying history: `git log -- <path>`
+recovers it. The exception is *unfinished intent* (a design never built, an
+open question still wanted) — that is live, not history, and must be harvested
+to a Gitea ticket before its file is deleted. A citation from a living doc or
+from code must be resolved before the cited file is deleted.
+
+## Consequences
+
+- The documentation map lists only current truth; there is no "historical" pile
+  to route around.
+- No agent, under any plugin or skill, writes process-markdown into the repo.
+  The rule is plugin-agnostic on purpose — it binds the agent, not a named tool.
+- History of deleted process docs is in git; unfinished intent is in the issue
+  tracker; rationale is in ADRs and law. Each thing has exactly one home.