refactor(service): disable SubmitFromApplication fallback, fully replaced by POST /tasks

- Comment out SubmitFromApplication method and its fallback path

- Comment out 5 tests that tested the old direct-submission code

- Remove unused imports after commenting out the method

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

internal/service/application_service_test.go

@@ -1,12 +1,8 @@
 package service
 
 import (
-	"context"
-	"encoding/json"
 	"net/http"
 	"net/http/httptest"
-	"os"
-	"path/filepath"
 	"strings"
 	"testing"
 
@@ -198,6 +194,8 @@ func TestRenderScript_NewlineInValue(t *testing.T) {
 	}
 }
 
+// [已禁用] 测试的是旧的直接提交路径，该路径已被注释掉
+/*
 func TestSubmitFromApplication_Success(t *testing.T) {
 	jobID := int32(42)
 	appSvc, cleanup := setupApplicationService(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -227,7 +225,10 @@ func TestSubmitFromApplication_Success(t *testing.T) {
 		t.Errorf("JobID = %d, want 42", resp.JobID)
 	}
 }
+*/
 
+// [已禁用] 测试的是旧的直接提交路径，该路径已被注释掉
+/*
 func TestSubmitFromApplication_AppNotFound(t *testing.T) {
 	appSvc, cleanup := setupApplicationService(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
@@ -242,7 +243,10 @@ func TestSubmitFromApplication_AppNotFound(t *testing.T) {
 		t.Errorf("error should mention 'not found', got: %v", err)
 	}
 }
+*/
 
+// [已禁用] 测试的是旧的直接提交路径，该路径已被注释掉
+/*
 func TestSubmitFromApplication_ValidationFail(t *testing.T) {
 	appSvc, cleanup := setupApplicationService(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
@@ -263,7 +267,10 @@ func TestSubmitFromApplication_ValidationFail(t *testing.T) {
 		t.Errorf("error should mention 'missing', got: %v", err)
 	}
 }
+*/
 
+// [已禁用] 测试的是旧的直接提交路径，该路径已被注释掉
+/*
 func TestSubmitFromApplication_NoParameters(t *testing.T) {
 	jobID := int32(99)
 	appSvc, cleanup := setupApplicationService(t, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -289,7 +296,10 @@ func TestSubmitFromApplication_NoParameters(t *testing.T) {
 		t.Errorf("JobID = %d, want 99", resp.JobID)
 	}
 }
+*/
 
+// [已禁用] 前端已全部迁移到 POST /tasks 接口，此测试不再需要。
+/*
 func TestSubmitFromApplication_DelegatesToTaskService(t *testing.T) {
 	jobID := int32(77)
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -354,3 +364,4 @@ func TestSubmitFromApplication_DelegatesToTaskService(t *testing.T) {
 		t.Errorf("task Status = %q, want %q", task.Status, model.TaskStatusQueued)
 	}
 }
+*/