feat(moderation): add background contribution burst detector and mode…

[shakourllahfashola-dev]

Summary

This PR implements the Suspicious Contribution Burst Detector and Moderation Flagging feature to identify anomalous or repeating wallet behavior indicating testnet manipulation.

Key Changes:

• Asynchronous Queueing: Contribution details (projectId, senderPublicKey, amount, timestamp, transactionHash) are pushed to a new BullMQ contribution-moderation queue asynchronously via .catch() on contribute() in CrowdfundService. This avoids blocking synchronous writes in the request path.
• Rule Engine: A background ContributionModerationProcessor checks the sorted contribution history using 4 rules:
  1. Velocity Alert: > 5 contributions within 10 seconds.
  2. Wallet Spammer Alert: Same wallet contributing > 3 times within 15 seconds.
  3. Large Amount Alert: Single contribution > 10,000 tokens or > 50% of target funding amount.
  4. Coordination Alert: > 4 unique wallets contributing within 30 seconds.
• Auto-moderation Flags: Automatically generates programmatic ContentReport entities under a dedicated, seeded system administrator account (system-detector@lumenpulse.com), feeding directly into the moderation review queue.
• Tests: Created comprehensive unit tests validating all rules in contribution-moderation.processor.spec.ts.

Linked Issue

Closes #851

Type of Change

• feat
• fix
• docs
• refactor
• test
• chore

Validation

• Lint passed for affected area(s)
• Tests passed for affected area(s)
• Manual verification completed (if applicable)

Documentation

• Documentation updated (or N/A with explanation)
• Screenshots/videos attached for UI changes

Checklist

• Branch name uses feat/, fix/, or docs/
• Commit messages follow Conventional Commits
• PR scope matches linked issue acceptance criteria

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[Cedarich]

@shakourllahfashola-dev Fix CI