chore: add project docs, glossary, research and opencode/fastcrw skills

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

docs/agents/domain.md

@@ -0,0 +1,35 @@
+# Domain Docs
+
+How the engineering skills should consume this repo's domain documentation when exploring the codebase.
+
+## Before exploring, read these
+
+- **`CONTEXT.md`** at the repo root
+- **`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 creates them lazily when terms or decisions actually get resolved.
+
+## File structure
+
+Single-context repo:
+
+```
+/
+├── CONTEXT.md
+├── docs/adr/
+│   ├── 0001-event-sourced-orders.md
+│   └── 0002-postgres-for-write-model.md
+└── src/
+```
+
+## 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-0007 (event-sourced orders) — but worth reopening because…_