fix: Initialize metrics on startup to fix restart gap; ProbeTx can be disabled

[KA-ROM]

Overview

• Added Enabled bool to ProbeTx config — probes now require both enabled: true and a private key to activate
• Init some metrics to 0 at startup for all known label combinations.

Fixes

• Added missing stream_type label to flashblocks_receive_failure_count

Why metric changes

After service restarts, metrics disappear until their first events occur — creating gaps in observability and preventing alerts from firing despite chain-monitor being healthy. This PR fixes that by initializing all synchronous metrics to 0 at startup for all known label combinations.

New metric

• FlashblocksStreamUp gauge to track stream connectivity (1=up, 0=down)

Metric zero-initialization at startup

• FlashblocksMonitor.initializeMetricsFlashblocksStreams(): initializes per-stream metrics for all configured private/public streams:
  • flashblocks_stream_up
  • flashblocks_receive_success_count
  • flashblocks_receive_failure_count
• BlockInspector.initializeMetrics(): initializes block inspector metrics:
  • blocks_seen_count, blocks_landed_count, blocks_missed_count, block_missed (always)
  • flashblocks_landed_count, flashblocks_missed_count (when flashblock number contract configured)
  • flashtestations_landed_count, flashtestations_missed_count, workload_added_to_policy_error_count (when builder policy contract configured)
  • registered_flashtestations_error_count (when flashtestation registry contract configured)

[Copilot]

Pull request overview

Ensures flashblocks stream metrics are present immediately after startup/restart by initializing metrics for all configured streams and adding a stream connectivity gauge.

Changes:

• Initialize flashblocks stream metrics to 0 for all configured streams during startup.
• Add flashblocks_stream_up gauge and record 1/0 on successful connect / failures.
• Standardize metric labels across flashblocks stream metrics (e.g., stream_type, network_id).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 4 comments.

File	Description
server/l2/flashblocks_monitor.go	Initializes per-stream metrics on startup; adds stream_type labeling and records flashblocks_stream_up on connect/failure paths.
metrics/metrics.go	Registers the new flashblocks_stream_up gauge instrument.
metrics/exports.go	Exports the new gauge and wires its setup into metric initialization.

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[Copilot]

This code sets fm.stop to cancel processingContext, but initializeMetricsFlashblocksStreams and the stream goroutines are started with ctx instead of processingContext. If fm.stop() is called, processingContext will be canceled but the streams may keep running (and continue recording metrics) because they’re not observing the canceled context. Pass processingContext to initializeMetricsFlashblocksStreams(...) and to readStream(...) so shutdown behaves as intended.