Add Claude agents and review-and-commit skill

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.claude/agents/go-conventions.md

@@ -0,0 +1,40 @@
+---
+description: Go conventions and patterns for this project
+globs: "**/*.go"
+alwaysApply: false
+---
+
+# Go Conventions
+
+## Context
+
+Every exported function that does I/O takes `context.Context` as its first argument.
+
+## Errors
+
+- Define package-level sentinel errors for expected conditions:
+
+```go
+var ErrNotFound = fmt.Errorf("not found")
+```
+
+- Wrap unexpected errors with `fmt.Errorf("doing X: %w", err)` to preserve the chain.
+- Callers check expected errors with `errors.Is(err, store.ErrNotFound)`.
+
+## UUIDs
+
+- Use `github.com/google/uuid` for all UUID types.
+- Model structs use `uuid.UUID`, not `string`, for ID fields.
+
+## Database
+
+- Use `?` parameter placeholders (MySQL style), never string interpolation.
+- Use `gen_random_uuid()` for server-generated UUIDs (Postgres built-in).
+- **Queries**: use [sqlc](https://sqlc.dev/) to generate type-safe Go from SQL.
+  Write annotated SQL in `internal/store/queries/*.sql`; run `task sqlc` to
+  regenerate. Never hand-write query code in Go — edit the `.sql` source instead.
+
+## Testing
+
+- Use the standard `testing` package. No external assertion libraries.
+- Test functions follow `TestTypeName_MethodName` naming