feat(provider): add native Anthropic Messages API adapter (Phase 2)

2026-07-03T09:03:13+00:00

Adds internal/provider/anthropic, the first genuinely new provider.Provider implementation on top of Phase 1's provider-neutral tool-use loop, alongside (not replacing) the existing Docker/CLI-subprocess ContainerRunner path for the "claude" agent type: - internal/provider/anthropic: translates the neutral ChatRequest/ChatResponse shape to/from Anthropic's Messages API content-block format (system as a top-level field, tool_use/tool_result blocks, no "tool" role -- tool results become user-role messages), with a per-model-prefix pricing table for CostUSD - internal/retry: IsRateLimitError additively extended to recognize Anthropic's rate_limit_error/overloaded_error/529 shapes - internal/config: RunnersConfig.Anthropic/AnthropicEnabled() gate - internal/cli/serve.go, run.go: register runners["anthropic"] as a NativeRunner when [providers.anthropic].api_key is set and enabled -- tracked as a distinct executions.agent="anthropic" budget bucket, separate from the CLI-subprocess "claude" runner even though both bill the same Anthropic account go build/vet/test -race all pass. No live Anthropic API key is available in this environment, so verification is via fake-httptest-server adapter tests (12 cases, incl. multi-turn tool_result round-trip and rate-limit error matching) plus a Pool/NativeRunner routing test proving agent.type: "anthropic" actually reaches the new provider. Live end-to-end verification against the real API is a follow-up once a key is configured. Co-Authored-By: Claude Sonnet 5 Claude-Session: https://claude.ai/code/session_01V1moSNCJRcP6kykA4tyUSs

claudomator.git/internal/provider/anthropic/anthropic_test.go, branch main

feat(provider): add native Anthropic Messages API adapter (Phase 2)