fix: grace poller checks pod liveness before giving up on log stream (FAR-52)

The K8s log client v1.x closes the follow-stream prematurely due to a
known upstream bug — causing the grace timer to fire 30 s after log
stream exit even when the container is still running.  The old behaviour
(`waitForPodTermination` with a hardcoded 120 s timeout) was too short
for agents whose opencode runs take several minutes, leading to premature
failure and issues stuck in `blocked`.

Fix: the grace poller now calls `readNamespacedPod` before resolving the
completion promise.  If the pod is still Running/Pending, it resets
`logExitTime` to defer the grace deadline.  A `graceCheckPending` guard
prevents concurrent checks.  A `graceMaxWaitMs` cap (= completionTimeoutMs
when set, 20 min otherwise) ensures we never wait forever for unlimited
jobs.  Version bumped to 0.1.21.

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

package.json

@@ -1,6 +1,6 @@
 {
   "name": "paperclip-adapter-opencode-k8s",
-  "version": "0.1.20",
+  "version": "0.1.21",
   "description": "Paperclip adapter plugin that runs OpenCode agents as Kubernetes Jobs",
   "license": "MIT",
   "type": "module",