feat: add host-driven GitHub Actions CI watcher (Level 3)

Replace LLM-per-tick polling with direct `gh api` calls for GitHub
Actions watchers. New `ci_provider` discriminator column routes tasks
to either the host-driven path (zero LLM tokens) or the existing
generic LLM path. GitHub watchers poll at 15s intervals (min 10s)
via `checkGitHubActionsRun()` in the scheduler, with completion
messages sent directly to chat on terminal state.

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

src/github-ci.ts

@@ -0,0 +1,199 @@
+import { execFile } from 'child_process';
+
+import { extractWatchCiTarget } from './task-watch-status.js';
+import type { ScheduledTask } from './types.js';
+
+export interface GitHubCiMetadata {
+  repo: string;
+  run_id: number;
+  poll_count?: number;
+  consecutive_errors?: number;
+}
+
+interface GitHubActionsRunResponse {
+  status?: string | null;
+  conclusion?: string | null;
+  name?: string | null;
+  display_title?: string | null;
+  html_url?: string | null;
+  head_branch?: string | null;
+  head_sha?: string | null;
+  event?: string | null;
+}
+
+interface GitHubActionsJobsResponse {
+  jobs?: Array<{
+    name?: string | null;
+    conclusion?: string | null;
+  }>;
+}
+
+export interface GitHubRunCheckResult {
+  terminal: boolean;
+  resultSummary: string;
+  completionMessage?: string;
+}
+
+function execGhApi(args: string[]): Promise<string> {
+  return new Promise((resolve, reject) => {
+    execFile(
+      'gh',
+      ['api', ...args],
+      {
+        maxBuffer: 10 * 1024 * 1024,
+        env: process.env,
+      },
+      (error, stdout, stderr) => {
+        if (error) {
+          const details = stderr?.trim() || stdout?.trim() || error.message;
+          reject(new Error(`gh api failed: ${details}`));
+          return;
+        }
+        resolve(stdout);
+      },
+    );
+  });
+}
+
+export function parseGitHubCiMetadata(
+  raw: string | null | undefined,
+): GitHubCiMetadata | null {
+  if (!raw) return null;
+
+  let parsed: Partial<GitHubCiMetadata>;
+  try {
+    parsed = JSON.parse(raw) as Partial<GitHubCiMetadata>;
+  } catch {
+    return null;
+  }
+  if (typeof parsed.repo !== 'string' || parsed.repo.trim() === '') {
+    return null;
+  }
+
+  const runId = Number(parsed.run_id);
+  if (!Number.isInteger(runId) || runId <= 0) {
+    return null;
+  }
+
+  return {
+    repo: parsed.repo,
+    run_id: runId,
+    poll_count:
+      Number.isInteger(parsed.poll_count) && parsed.poll_count! >= 0
+        ? parsed.poll_count
+        : undefined,
+    consecutive_errors:
+      Number.isInteger(parsed.consecutive_errors) &&
+      parsed.consecutive_errors! >= 0
+        ? parsed.consecutive_errors
+        : undefined,
+  };
+}
+
+export function serializeGitHubCiMetadata(
+  metadata: GitHubCiMetadata,
+): string {
+  return JSON.stringify(metadata);
+}
+
+function formatConclusionLabel(conclusion: string | null | undefined): string {
+  switch (conclusion) {
+    case 'success':
+      return '성공';
+    case 'failure':
+      return '실패';
+    case 'cancelled':
+      return '취소됨';
+    case 'timed_out':
+      return '시간 초과';
+    case 'action_required':
+      return '조치 필요';
+    case 'neutral':
+      return '중립';
+    case 'skipped':
+      return '건너뜀';
+    case 'stale':
+      return '오래됨';
+    default:
+      return conclusion || '완료';
+  }
+}
+
+async function fetchFailedJobs(
+  metadata: GitHubCiMetadata,
+): Promise<string[]> {
+  const stdout = await execGhApi([
+    `repos/${metadata.repo}/actions/runs/${metadata.run_id}/jobs?per_page=100`,
+  ]);
+  const parsed = JSON.parse(stdout) as GitHubActionsJobsResponse;
+  return (parsed.jobs || [])
+    .filter(
+      (job) =>
+        job.conclusion &&
+        ['failure', 'cancelled', 'timed_out', 'startup_failure'].includes(
+          job.conclusion,
+        ),
+    )
+    .map((job) => job.name?.trim())
+    .filter((name): name is string => Boolean(name))
+    .slice(0, 3);
+}
+
+export async function checkGitHubActionsRun(
+  task: Pick<ScheduledTask, 'prompt' | 'ci_metadata'>,
+): Promise<GitHubRunCheckResult> {
+  const metadata = parseGitHubCiMetadata(task.ci_metadata);
+  if (!metadata) {
+    throw new Error('Task is missing valid GitHub CI metadata');
+  }
+
+  const stdout = await execGhApi([
+    `repos/${metadata.repo}/actions/runs/${metadata.run_id}`,
+  ]);
+  const run = JSON.parse(stdout) as GitHubActionsRunResponse;
+  const status = run.status || 'unknown';
+
+  if (status !== 'completed') {
+    return {
+      terminal: false,
+      resultSummary: `GitHub Actions run ${metadata.run_id} is ${status}`,
+    };
+  }
+
+  let failedJobs: string[] = [];
+  try {
+    failedJobs = await fetchFailedJobs(metadata);
+  } catch {
+    failedJobs = [];
+  }
+
+  const target =
+    extractWatchCiTarget(task.prompt) ||
+    `GitHub Actions run ${metadata.run_id}`;
+  const conclusionLabel = formatConclusionLabel(run.conclusion);
+
+  const lines = [
+    `CI 완료: ${target}`,
+    `판정: ${conclusionLabel}`,
+    `- 저장소: ${metadata.repo}`,
+  ];
+
+  if (run.name) {
+    lines.push(`- 워크플로: ${run.name}`);
+  }
+  if (run.head_branch) {
+    lines.push(`- 브랜치: ${run.head_branch}`);
+  }
+  if (failedJobs.length > 0) {
+    lines.push(`- 실패 job: ${failedJobs.join(', ')}`);
+  }
+  if (run.html_url) {
+    lines.push(`- 링크: ${run.html_url}`);
+  }
+
+  return {
+    terminal: true,
+    resultSummary: `${conclusionLabel}: ${metadata.repo} run ${metadata.run_id}`,
+    completionMessage: lines.join('\n'),
+  };
+}