#445 fix: send scheduled campaigns on BullMQ 5

Scheduled campaigns never leave SCHEDULED on BullMQ 5. The batch queue uses a custom job ID containing a colon, which BullMQ rejects with "Custom Id cannot contain :".

This changes the separator to a hyphen and adds a regression test at the CampaignBatchService.queueBatch call site.

Verification:

• Reproduced against a deployed self-hosted instance
• Confirmed the new test fails before the fix
• Focused campaign service tests: 6 passed
• Full web unit suite: 121 passed
• Web typecheck passed
• Focused ESLint passed
• Production verification after the same fix: a scheduled campaign completed 1/1

Migration notes: none. No schema, configuration, or dependency changes.

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Summary by cubic

Scheduled campaigns on bullmq 5 were stuck in SCHEDULED because the batch queue used a custom job ID with a colon, which bullmq rejects. We now use a hyphenated job ID, so campaigns enqueue and execute.

• CampaignBatchService.queueBatch sets jobId to "campaign-batch-" (was "campaign-batch:"); preserves deterministic idempotency.
• Adds a regression test that asserts a BullMQ-compatible job ID and verifies Queue.add receives the expected arguments; adjusts test mocks to spy on queue and contact updates.
• No schema, configuration, or dependency changes; no migration actions.

Summary by CodeRabbit

• Bug Fixes
  • Improved campaign batch processing by ensuring queued jobs use compatible identifiers.
• Tests
  • Expanded coverage for campaign batch queuing and contact subscription updates.
  • Updated test scenarios to verify queued job details and webhook-related behavior.