feat: foundations — canonical types, Parse grammar, env DSNs, health, chains

Phase 1 of the majordomo build:
- llm/ canonical contract (messages, parts, tools, capabilities, streaming,
  Model/Provider, error classification)
- health/ clock-injected tracker (threshold bench, exponential capped
  cooldown, reset-on-success)
- root Registry + Parse (verbatim model ids, inline recursive alias
  expansion with cycle detection, chain dedup), LLM_* env-DSN providers
  (go-llm parity: lazy fallback + eager LoadEnv), health-aware chain
  executor behind the Model interface
- provider/fake scriptable test provider; hermetic test suite incl. the
  trailing-thinking chain and foreman:// env loading
- ADRs 0001-0008, CLAUDE.md, README (honest matrix), CI workflow,
  docs/phase-1-design.md

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

builtin.go

@@ -0,0 +1,82 @@
+package majordomo
+
+import (
+	"context"
+	"fmt"
+
+	"gitea.stevedudenhoeffer.com/steve/majordomo/llm"
+)
+
+// Built-in provider names. Real client implementations land per-phase
+// (see progress.md); until a provider's phase ships, its registration is a
+// stub that resolves (so specs parse and env DSNs load) but errors on use.
+const (
+	ProviderOpenAI      = "openai"
+	ProviderAnthropic   = "anthropic"
+	ProviderGoogle      = "google"
+	ProviderOllama      = "ollama"
+	ProviderOllamaCloud = "ollama-cloud"
+	ProviderForeman     = "foreman"
+)
+
+// registerBuiltins installs the built-in providers and env-DSN scheme
+// factories into a fresh registry.
+func registerBuiltins(r *Registry) {
+	stub := func(kind string) SchemeFactory {
+		return func(name string, dsn DSN) (llm.Provider, error) {
+			return &stubProvider{name: name, kind: kind, baseURL: dsn.BaseURL(), token: dsn.Token}, nil
+		}
+	}
+
+	for _, kind := range []string{
+		ProviderOpenAI, ProviderAnthropic, ProviderGoogle,
+		ProviderOllama, ProviderOllamaCloud, ProviderForeman,
+	} {
+		r.providers[kind] = &stubProvider{name: kind, kind: kind}
+		r.schemes[kind] = stub(kind)
+	}
+	// "gemini" is an alternate scheme for the Google provider.
+	r.schemes["gemini"] = stub(ProviderGoogle)
+}
+
+// stubProvider stands in for a provider implementation that lands in a
+// later phase. It resolves and carries its connection details (so Parse,
+// chains, and env loading are fully functional) but errors on use.
+type stubProvider struct {
+	name    string
+	kind    string
+	baseURL string
+	token   string
+}
+
+func (s *stubProvider) Name() string { return s.name }
+
+func (s *stubProvider) Model(id string, opts ...llm.ModelOption) (llm.Model, error) {
+	cfg := llm.ApplyModelOptions(opts)
+	return &stubModel{provider: s, id: id, cfg: cfg}, nil
+}
+
+type stubModel struct {
+	provider *stubProvider
+	id       string
+	cfg      llm.ModelConfig
+}
+
+func (m *stubModel) err() error {
+	return fmt.Errorf("majordomo: provider %q (%s) is not implemented yet", m.provider.name, m.provider.kind)
+}
+
+func (m *stubModel) Generate(context.Context, llm.Request, ...llm.Option) (*llm.Response, error) {
+	return nil, m.err()
+}
+
+func (m *stubModel) Stream(context.Context, llm.Request, ...llm.Option) (llm.Stream, error) {
+	return nil, m.err()
+}
+
+func (m *stubModel) Capabilities() llm.Capabilities {
+	if m.cfg.Capabilities != nil {
+		return *m.cfg.Capabilities
+	}
+	return llm.Capabilities{}
+}