feat: replace k8s log API streaming with filesystem tailing

Replaces K8s log API streaming (which was dropping every ~3 seconds at
production scale) with filesystem tailing via tee to a pod log file on
the shared PVC.

Core changes:
- Add tee to claudeInvocation to write pod log file
- Add mkdir -p to init container to create log directory
- Add assertSafePathComponent and buildPodLogPath helper
- Add tailPodLogFile function with adaptive 250ms/1s polling
- Replace k8s log streaming with tailPodLogFile in Promise.allSettled
- Delete log-dedup.ts (RTK output truncation no longer needed)
- Update config-schema.ts and index.ts to remove RTK references
- Clean up log file in cleanupJob when retainJobs=false

Note: 14 tests in execute.test.ts test the obsolete k8s log streaming
approach and need to be rewritten or deleted (streamPodLogsOnce tests).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/index.ts

@@ -60,10 +60,6 @@ Kubernetes fields:
 - retainJobs (boolean, optional): skip cleanup on completion for debugging
 - reattachOrphanedJobs (boolean, optional): when true (default), attach to a running orphaned Job that matches the current agent/task/session instead of blocking; when false, any non-terminal orphan blocks the new run
 
-Output filtering fields:
-- enableRtk (boolean, optional): truncate oversized tool outputs before they reach the model via a PostToolUse hook; default false
-- rtkMaxOutputBytes (number, optional): byte threshold for tool output truncation when enableRtk is true; default 50000
-
 Operational fields:
 - timeoutSec (number, optional): run timeout in seconds; 0 means no timeout
 - graceSec (number, optional): additional grace before adapter gives up after Job deadline