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>

.gitea/workflows/ci.yaml

@@ -0,0 +1,26 @@
+name: CI
+on:
+  push: { branches: ["*"] }
+  pull_request: { branches: ["*"] }
+jobs:
+  build:
+    name: Build & Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with: { go-version-file: "go.mod" }
+      - run: go mod download
+      - run: go build ./...
+      - run: go vet ./...
+      - run: go test -race -count=1 ./...
+  tidy:
+    name: Tidy
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with: { go-version-file: "go.mod" }
+      - run: |
+          go mod tidy
+          git diff --exit-code go.mod go.sum