refactor(executor): extract provider-neutral tool-use loop (Phase 1)

Splits LocalRunner's OpenAI-specific agentic loop into reusable, provider-
agnostic pieces so later phases can add native Anthropic/OpenAI/Google/Groq/
OpenRouter adapters without duplicating the control flow:

- internal/provider: neutral Provider/ChatRequest/ChatResponse types, plus
  an openaicompat adapter wrapping the existing internal/llm.Client unchanged
- internal/sandbox: Sandbox interface + HostSandbox (git clone/push/cleanup,
  read_file/write_file/run_bash/glob), lifted verbatim from local.go/localtools.go
- internal/agentloop: the extracted tool-use loop (request/response/tool-
  dispatch/loop, ask_user blocking, stream-json envelope, summary fallback)
- internal/agentchannel: AgentChannel/SubtaskSpec/BlockedError/ErrAgentBlocked
  moved out of internal/executor so agentloop can use them without an import
  cycle; internal/executor re-exports via type aliases, so no call site changes
- internal/executor/nativerunner.go: NativeRunner replaces LocalRunner,
  wiring agentloop.Loop + openaicompat + HostSandbox together
- config.Providers map[string]ProviderConfig added (unused until Phase 2+)

Zero intended behavior change: go test -race ./... passes across all
packages, and end-to-end stream-json/summary/changestats output was verified
byte-compatible against a fake OpenAI-compatible server. Adds test coverage
for sandbox tool-dispatch (git clone/push, read/write/bash/glob) that
LocalRunner never had.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01V1moSNCJRcP6kykA4tyUSs

1 files changed, 4 insertions, 2 deletions

diff --git a/internal/cli/serve.go b/internal/cli/serve.go
index 19db2f8..d8ec6a1 100644
--- a/internal/cli/serve.go
+++ b/internal/cli/serve.go
@@ -15,6 +15,7 @@ import (
 	"github.com/thepeterstone/claudomator/internal/config"
 	"github.com/thepeterstone/claudomator/internal/executor"
 	"github.com/thepeterstone/claudomator/internal/notify"
+	"github.com/thepeterstone/claudomator/internal/provider/openaicompat"
 	"github.com/thepeterstone/claudomator/internal/storage"
 	"github.com/thepeterstone/claudomator/internal/version"
 	"github.com/spf13/cobra"
@@ -139,11 +140,12 @@ func serve(addr, basePath string) error {
 
 	localClient := buildLocalLLMClient(cfg.LocalModel, logger)
 	if localClient != nil && cfg.Runners.LocalEnabled() {
-		runners["local"] = &executor.LocalRunner{
-			Client:             localClient,
+		runners["local"] = &executor.NativeRunner{
+			Provider:           openaicompat.New(localClient),
 			Logger:             logger,
 			LogDir:             cfg.LogDir,
 			DefaultTemperature: cfg.LocalModel.DefaultTemperature,
+			DefaultModel:       cfg.LocalModel.Model,
 		}
 		logger.Info("local runner registered", "endpoint", cfg.LocalModel.Endpoint, "model", cfg.LocalModel.Model)
 	}