fix(server): make tailPodLogFile exit on job completion + port c8429cf

- Run tailPodLogFile and waitForJobCompletion in parallel via Promise.allSettled;
  completion sets stopSignal.stopped so the tail loop drains and exits. Without
  this, tailPodLogFile loops forever — the only natural exit was fh.stat()
  throwing on file removal, which never happened during normal job completion.
- Restructure tail loop to read-then-sleep, with a final drain after stopSignal
  is set to capture bytes written between the last poll and terminal state.
- Port the c8429cf fix from paperclip-adapter-claude-k8s:
  * buildPodLogPath now writes to /paperclip/instances/default/data/run-logs/...
    to match the server PVC layout (the /data/ segment was missing).
  * Drop the mkdir -p ... && from both init container command variants — the
    PVC isn't mounted in the init container, so the mkdir was failing with
    exit code 1 and the && short-circuit prevented the prompt copy.
- Test infrastructure:
  * Hoisted fs/promises mock now uses importOriginal so readFile (used for
    skill bundle loading) hits the real implementation.
  * setMockJsonl() lets individual tests inject specific JSONL into the tail's
    read buffer (previously dead constants in the test file).
  * fh.read mock now writes into the caller's buffer instead of returning a
    separate one.
- Add src/server/test.test.ts covering testEnvironment (was 0% → 98.5% stmts).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "paperclip-adapter-opencode-k8s",
-  "version": "0.1.39",
+  "version": "0.1.40",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "paperclip-adapter-opencode-k8s",
-      "version": "0.1.39",
+      "version": "0.1.40",
       "license": "MIT",
       "dependencies": {
         "@kubernetes/client-node": "^1.0.0",