feat: NanoClaude Phase 1 — 비동기 job 기반 AI Gateway 코어 구현

POST /chat → job_id ACK, GET /chat/{job_id}/stream → SSE 스트리밍,
EXAONE Ollama adapter, JobManager, StateStream, Worker 구조

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

nanoclaude/services/job_manager.py

@@ -0,0 +1,57 @@
+"""JobManager — job lifecycle: create, track status, cancel."""
+
+from __future__ import annotations
+
+import asyncio
+import uuid
+from dataclasses import dataclass, field
+from time import time
+
+from models.schemas import JobStatus
+
+
+@dataclass
+class Job:
+    id: str
+    message: str
+    status: JobStatus = JobStatus.queued
+    created_at: float = field(default_factory=time)
+    task: asyncio.Task | None = field(default=None, repr=False)
+
+
+class JobManager:
+    def __init__(self) -> None:
+        self._jobs: dict[str, Job] = {}
+
+    def create(self, message: str) -> Job:
+        job_id = uuid.uuid4().hex[:12]
+        job = Job(id=job_id, message=message)
+        self._jobs[job_id] = job
+        return job
+
+    def get(self, job_id: str) -> Job | None:
+        return self._jobs.get(job_id)
+
+    def set_status(self, job_id: str, status: JobStatus) -> None:
+        job = self._jobs.get(job_id)
+        if job:
+            job.status = status
+
+    def cancel(self, job_id: str) -> bool:
+        job = self._jobs.get(job_id)
+        if not job:
+            return False
+        if job.status in (JobStatus.completed, JobStatus.failed, JobStatus.cancelled):
+            return False
+        job.status = JobStatus.cancelled
+        if job.task and not job.task.done():
+            job.task.cancel()
+        return True
+
+    def attach_task(self, job_id: str, task: asyncio.Task) -> None:
+        job = self._jobs.get(job_id)
+        if job:
+            job.task = task
+
+
+job_manager = JobManager()