Preserve uint64 fingerprints in alert history and triage timelines

[jpowersdev]

Problem

Alert history fingerprints can lose precision when the backend returns an Alertmanager uint64 as a JSON number above Number.MAX_SAFE_INTEGER.

In a live read-only test with @jpowersdev/signoz@1.2.0, one alerts triage response represented the same labeled alert instance differently across sections:

• topContributors[0].fingerprint: "13794282291722923096" (precision-preserving string)
• matching timeline event fingerprint: 13794282291722924000 (rounded JavaScript number)

alerts history <rule-id> --output json emitted the same rounded numeric value.

The top-contributors endpoint already avoids this by rewriting large unquoted fingerprint values to strings before JSON.parse. Rule-history timeline decoding still goes through the generated client and loses precision first.

Impact

Automation cannot reliably join timeline/history events to top contributors or other Alertmanager data by fingerprint. The JSON type also differs between related command sections.

Reproduction

1. Use a rule whose Alertmanager fingerprint exceeds Number.MAX_SAFE_INTEGER.
2. Run signoz alerts triage <rule-id> --output json.
3. Compare the sole top-contributor fingerprint with the matching timeline event.
4. Run signoz alerts history <rule-id> --output json and compare again.

Acceptance criteria

• Preserve exact uint64 fingerprints in alerts history and triage timeline output.
• Emit fingerprints consistently as decimal strings across history, timeline, and top-contributor JSON.
• Add tests using values above Number.MAX_SAFE_INTEGER that would otherwise round.
• Keep existing table and stream output readable and backward-compatible where practical.
• Do not regress the precision-safe top-contributor decoder.