docs: record agent skill config, symlink CLAUDE.md to AGENTS.md

Adds docs/agents/{issue-tracker,triage-labels,domain}.md so the engineering
skills know where issues live (Gitea via tea, not gh), which triage labels to
apply, and that domain docs are single-context.

Every CLAUDE.md was a stale subset of the AGENTS.md beside it, so each is now
a symlink and AGENTS.md is the single source of truth.

docs/agents/domain.md

@@ -0,0 +1,47 @@
+# Domain Docs
+
+How the engineering skills should consume this repo's domain documentation when exploring the
+codebase. Layout: **single-context** — one `CONTEXT.md` plus `docs/adr/` at the repo root.
+
+## Before exploring, read these
+
+- **`CONTEXT.md`** at the repo root — the glossary / ubiquitous language.
+- **`docs/adr/`** — read ADRs that touch the area you're about to work in.
+
+If any of these files don't exist, **proceed silently**. Don't flag their absence; don't suggest
+creating them upfront. The `/domain-modeling` skill (reached via `/grill-with-docs` and
+`/improve-codebase-architecture`) creates them lazily when terms or decisions actually get resolved.
+
+Neither exists yet in this repo. The existing `AGENTS.md` / `CLAUDE.md` and `docs/design-system.md`
+carry the current architecture and design law — read those regardless.
+
+## File structure
+
+```
+/
+├── CONTEXT.md
+├── docs/adr/
+│   ├── 0001-....md
+│   └── 0002-....md
+├── backend/
+└── userscript/
+```
+
+If this repo ever splits into genuinely separate contexts, add a root `CONTEXT-MAP.md` pointing at
+one `CONTEXT.md` per context and update this file.
+
+## Use the glossary's vocabulary
+
+When your output names a domain concept (in an issue title, a refactor proposal, a hypothesis, a
+test name), use the term as defined in `CONTEXT.md`. Don't drift to synonyms the glossary
+explicitly avoids.
+
+If the concept you need isn't in the glossary yet, that's a signal — either you're inventing
+language the project doesn't use (reconsider) or there's a real gap (note it for
+`/domain-modeling`).
+
+## Flag ADR conflicts
+
+If your output contradicts an existing ADR, surface it explicitly rather than silently overriding:
+
+> _Contradicts ADR-0002 (…) — but worth reopening because…_