feat: monitor tasks, Prometheus metrics, and seictl v0.0.24

[bdchatham]

Summary

• Adds monitor task infrastructure — a third task category that the controller submits once in Running phase, polls each reconcile, and reacts to on completion with Conditions, Events, and Prometheus metrics
• First monitor task: result-export comparison mode — sidecar compares block results against a canonical RPC and completes on app-hash divergence
• Sidecar-lost-task detection via ErrNotFound after synchronous submission
• ResultExportComplete Condition with reasons DivergenceDetected, TaskFailed, TaskLost
• Prometheus metrics: sei_controller_monitor_task_completed_total (counter) and sei_controller_monitor_task_status (gauge)
• Renames PlannedTaskStatus → TaskStatus for cross-context clarity
• Removes dead scheduled-mode result-export code (CanonicalRPC is now required)
• Bumps seictl to v0.0.24 and sidecar image to sha256:63860a7c

Test plan

• ensureMonitorTask: submit once, idempotent skip, submit error
• pollMonitorTasks: completed, failed, still running, skip completed, sidecar lost task, invalid UUID, transient error, unknown error
• reconcileRuntimeTasks: monitor mode submission, replayer without ResultExport, poll requeue, conflict early return
• Planner: ResultExportMonitorTask returns/nil for all node types
• Conditions verified on all terminal paths
• make manifests generate — CRDs regenerated
• golangci-lint run — 0 issues
• Full test suite passes