CAMEL-20227: Fix Pausable EIP losing messages due to Kafka offset advancement

[davsclaus]

Summary

Claude Code on behalf of Claus Ibsen

Fixes the Pausable EIP with Kafka consumer losing messages when the consumer is paused and later resumed. The root cause was that KafkaConsumerListener.afterConsume() never called consumer.pause() or seeked back to committed offsets, so consumer.poll() kept advancing offsets for records that were never processed.

• Rewrite afterConsume() to always evaluate the resume predicate, call consumer.pause() + seekConsumer() when pausing, and consumer.resume() when resuming
• Remove the paused boolean flag that prevented proper predicate evaluation
• Extract seekConsumer() helper shared between afterConsume and afterProcess
• Use Kafka's native consumer.pause() so poll() returns empty records during pause (no Thread.sleep needed)

Prior partial fix (869e870952c2) only added a paused flag without addressing the offset advancement. A full fix existed on the unmerged origin/kafka-pause branch — this PR adapts that fix to current main with the cleaner consumer.pause() approach.

Test plan

• Existing KafkaPausableConsumerIT passes — verifies all messages are received after pause/resume
• Existing KafkaPausableConsumerCircuitBreakerIT passes
• Verify no messages are lost when autoCommitEnable=true during pause/resume cycle

🤖 Generated with Claude Code

[github-actions]

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🧪 CI tested the following changed modules:

• components/camel-kafka

⚠️ Some tests are disabled on GitHub Actions (@DisabledIfSystemProperty(named = "ci.env.name")) and require manual verification:

• components/camel-kafka: 2 test(s) disabled on GitHub Actions

All tested modules (8 modules)

• Camel :: JBang :: MCP
• Camel :: JBang :: Plugin :: Route Parser
• Camel :: JBang :: Plugin :: TUI
• Camel :: JBang :: Plugin :: Validate
• Camel :: Kafka
• Camel :: Launcher :: Container
• Camel :: YAML DSL :: Validator
• Camel :: YAML DSL :: Validator Maven Plugin

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