merge: integrate oss branch — budget gating, MCP back-channel, events, loopback-only bind

Key features from OSS branch:
- Budget gating: rolling per-provider spend caps with BUDGET_EXCEEDED task state
- Agent MCP back-channel: runners mint tokens; /mcp endpoint resolves them
- Chatbot MCP server at /chatbot/mcp (requires api_token in config)
- Event timeline: unified event stream replacing ad-hoc question/summary flows
- Loopback-only default bind (127.0.0.1:8484); external_bind_allowed=true to expose
- repository_url required on task creation (enforces traceability)
- Auto-checker: spawns verification task after each execution

Conflict resolutions:
- serve.go: keep cfg.Runners.XEnabled() conditional registration from main + agentRegistry from oss
- config.go: keep RunnersConfig from main + BudgetConfig/ExternalBindAllowed from oss
- server.go: handleStaticFiles (base-path rewrite) kept; deduplicated duplicate from both sides
- executor/claude.go: accepted oss deletion (ClaudeRunner replaced by ContainerRunner)
- container_test.go: added noopChannel + AgentChannel parameter to Run call

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

1 files changed, 40 insertions, 0 deletions

diff --git a/internal/llm/client_test.go b/internal/llm/client_test.go
index 8257836..7533a8a 100644
--- a/internal/llm/client_test.go
+++ b/internal/llm/client_test.go
@@ -157,3 +157,43 @@ func TestErrFromStatus_RateLimitMarker(t *testing.T) {
 		t.Errorf("error should embed retry-after, got: %v", err)
 	}
 }
+
+func TestChat_ToolsRoundTrip(t *testing.T) {
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var body openAIRequest
+		if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+			t.Fatalf("decode body: %v", err)
+		}
+		if len(body.Tools) != 1 || body.Tools[0].Function.Name != "do_thing" {
+			t.Errorf("tools not forwarded in request: %+v", body.Tools)
+		}
+		w.Header().Set("Content-Type", "application/json")
+		fmt.Fprintln(w, `{
+			"model": "m",
+			"choices": [{"message": {"role": "assistant", "content": "",
+				"tool_calls": [{"id": "call_1", "type": "function",
+					"function": {"name": "do_thing", "arguments": "{\"x\":1}"}}]},
+				"finish_reason": "tool_calls"}],
+			"usage": {"prompt_tokens": 3, "completion_tokens": 4}
+		}`)
+	}))
+	defer srv.Close()
+
+	c := &Client{Endpoint: srv.URL + "/v1", Model: "m"}
+	resp, err := c.Chat(context.Background(), ChatRequest{
+		Messages: []Message{{Role: "user", Content: "go"}},
+		Tools: []Tool{{Type: "function", Function: ToolFunction{
+			Name: "do_thing", Description: "d", Parameters: map[string]any{"type": "object"},
+		}}},
+	})
+	if err != nil {
+		t.Fatalf("Chat: %v", err)
+	}
+	if len(resp.ToolCalls) != 1 {
+		t.Fatalf("expected 1 tool call, got %d", len(resp.ToolCalls))
+	}
+	tc := resp.ToolCalls[0]
+	if tc.ID != "call_1" || tc.Function.Name != "do_thing" || tc.Function.Arguments != `{"x":1}` {
+		t.Errorf("unexpected tool call parsed: %+v", tc)
+	}
+}