feat(delivery): add AWX API client

Implement AWXClient with Launch, GetJob, and Cancel methods for
orchestrating Ansible job templates via AWX REST API. Uses Bearer
token auth with 30s timeout. Includes unit tests with mock transport.

Relates-to: #97

server/internal/service/awx_test.go

@@ -0,0 +1,39 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+)
+
+type roundTripFunc func(*http.Request) (*http.Response, error)
+
+func (f roundTripFunc) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }
+
+func TestAWXClientLaunchAndGetJob(t *testing.T) {
+	client := NewAWXClient("https://awx.example", "token")
+	client.client.Transport = roundTripFunc(func(r *http.Request) (*http.Response, error) {
+		if r.Header.Get("Authorization") != "Bearer token" {
+			t.Fatalf("missing auth header")
+		}
+		job := AWXJob{ID: 42, Status: "pending"}
+		if r.URL.Path == "/api/v2/jobs/42/" {
+			job.Status = "successful"
+		} else if r.URL.Path != "/api/v2/job_templates/7/launch/" {
+			t.Fatalf("unexpected path %s", r.URL.Path)
+		}
+		raw, _ := json.Marshal(job)
+		return &http.Response{StatusCode: http.StatusOK, Status: "200 OK", Body: io.NopCloser(bytes.NewReader(raw)), Header: make(http.Header)}, nil
+	})
+	job, err := client.Launch(context.Background(), 7, AWXLaunchRequest{InventoryID: 3, ExtraVars: map[string]any{"task_id": "t"}})
+	if err != nil || job.ID != 42 {
+		t.Fatalf("launch = %#v, err=%v", job, err)
+	}
+	job, err = client.GetJob(context.Background(), "42")
+	if err != nil || job.Status != "successful" {
+		t.Fatalf("get job = %#v, err=%v", job, err)
+	}
+}