refactor(jobengine): delete TaskRunner service

- Remove TaskRunner source, tests, libraries (3 directories)
- Remove from compose, services-matrix, nginx, hosts, smoke tests
- Remove CLI commands, UI references, Authority scopes
- Remove docs, OpenAPI spec, QA state files
- Leave task_runner_id DB columns as nullable legacy
- PacksRegistry preserved (independent service)
- Eliminates 2 containers (taskrunner-web + taskrunner-worker)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/Web/StellaOps.Web/src/app/core/api/jobengine-jobs.client.ts

@@ -33,7 +33,7 @@ export interface JobEngineJobRecord {
   readonly maxAttempts: number;
   readonly correlationId?: string | null;
   readonly workerId?: string | null;
-  readonly taskRunnerId?: string | null;
+  /** @deprecated taskRunnerId removed — nullable legacy column */
   readonly createdAt: string;
   readonly scheduledAt?: string | null;
   readonly leasedAt?: string | null;
@@ -87,7 +87,7 @@ interface JobEngineJobApiRecord {
   readonly maxAttempts?: number;
   readonly correlationId?: string | null;
   readonly workerId?: string | null;
-  readonly taskRunnerId?: string | null;
+  /** @deprecated taskRunnerId removed — nullable legacy column */
   readonly createdAt?: string;
   readonly scheduledAt?: string | null;
   readonly leasedAt?: string | null;
@@ -217,7 +217,7 @@ export class JobEngineJobsClient {
       maxAttempts: job.maxAttempts ?? 0,
       correlationId: job.correlationId ?? null,
       workerId: job.workerId ?? null,
-      taskRunnerId: job.taskRunnerId ?? null,
+
       createdAt: job.createdAt ?? new Date().toISOString(),
       scheduledAt: job.scheduledAt ?? null,
       leasedAt: job.leasedAt ?? null,

src/Web/StellaOps.Web/src/app/features/release-orchestrator/releases/create-release/pipeline-to-workflow.service.ts

@@ -425,7 +425,7 @@ export class PipelineToWorkflowService {
         $type: 'call-transport',
         stepName: `test-${config.testType}`,
         invocation: {
-          address: { $type: 'microservice', microserviceName: 'taskrunner', command: `execute-${config.testType}-test` },
+          address: { $type: 'microservice', microserviceName: 'scheduler', command: `execute-${config.testType}-test` },
           payloadExpression: obj([
             { name: 'releaseId', expression: path('state.releaseId') },
             { name: 'environment', expression: path('state.targetEnvironment') },