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/agents/triage-labels.md

@@ -0,0 +1,15 @@
+# Triage Labels
+
+The skills speak in terms of five canonical triage roles. This file maps those roles to the actual label strings used in this repo's issue tracker (Gitea — see `issue-tracker.md` for how to apply labels with `tea`).
+
+| Label in mattpocock/skills | Label in our tracker | Meaning                                  |
+| -------------------------- | -------------------- | ---------------------------------------- |
+| `needs-triage`             | `needs-triage`       | Maintainer needs to evaluate this issue  |
+| `needs-info`               | `needs-info`         | Waiting on reporter for more information |
+| `ready-for-agent`          | `ready-for-agent`    | Fully specified, ready for an AFK agent  |
+| `ready-for-human`          | `ready-for-human`    | Requires human implementation            |
+| `wontfix`                  | `wontfix`            | Will not be actioned                     |
+
+When a skill mentions a role (e.g. "apply the AFK-ready triage label"), use the corresponding label string from this table.
+
+Edit the right-hand column to match whatever vocabulary you actually use.