Kafka source issues after upgrade to edge: PollExceeded errors and consumption problems

Describe the bug
After upgrading from commit qw-airmail-20250522-hotfix (488375a9) to edge (660388a42756a739d0ef0aecd234ca953b85caf5), we are experiencing Kafka source failures.

error_log.txt

2025-12-09 16:45:58.757 | PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded)) |  
-- | -- | --
  |   | 2025-12-09 16:45:58.757 | 2025-12-09T07:45:58.757Z ERROR quickwit_actors::actor_context: exit activating-kill-switch actor=SourceActor-proud-RYA5 exit_status=Failure(Message consumption error: PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded) |  
  |   | 2025-12-09 16:45:58.757 | PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded)) |  
  |   | 2025-12-09 16:45:58.757 | 2025-12-09T07:45:58.757Z ERROR quickwit_actors::spawn_builder: actor-exit actor_id="SourceActor-proud-RYA5" phase=handling(quickwit_indexing::source::Loop) exit_status=Failure(Message consumption error: PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded) |  
  |   | 2025-12-09 16:45:58.476 | 2025-12-09T07:45:58.476Z ERROR rdkafka::client: librdkafka: Global error: PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded): Application maximum poll interval (600000ms) exceeded by 16ms |  
  |   | 2025-12-09 16:45:50.710 | PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded)) |  
  |   | 2025-12-09 16:45:50.710 | 2025-12-09T07:45:50.710Z ERROR quickwit_actors::actor_context: exit activating-kill-switch actor=SourceActor-polished-D8qx exit_status=Failure(Message consumption error: PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded) |  
  |   | 2025-12-09 16:45:50.710 | PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded)) |  
  |   | 2025-12-09 16:45:50.710 | 2025-12-09T07:45:50.710Z ERROR quickwit_actors::spawn_builder: actor-exit actor_id="SourceActor-polished-D8qx" phase=handling(quickwit_indexing::source::Loop) exit_status=Failure(Message consumption error: PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded) |  
  |   | 2025-12-09 16:45:50.710 | 2025-12-09T07:45:50.710Z ERROR rdkafka::client: librdkafka: Global error: PollExceeded (Local: Maximum application poll interval (max.poll.interval.ms) exceeded): Application maximum poll interval (600000ms) exceeded by 185ms

Steps to reproduce (if applicable)
Steps to reproduce the behavior:

1. Run indexing under sustained high load where backpressure occurs
   2 .Observe PollExceeded errors or consumption stalls

Expected behavior
Kafka source should continue consuming messages under high load without max.poll.interval.ms exceeded errors, as it did in the previous version (qw-airmail-20250522-hotfix).

Configuration:
Please provide:

1. Quickwit Version(edge: 660388a42756a739d0ef0aecd234ca953b85caf5)
2. The index_config.yaml

version: 0.8

index_id: log.common.access_log_v2_quickwit

doc_mapping:
  field_mappings:
    - name: id
      type: text
      tokenizer: raw
      description: "unique identifier for the event"
    - name: specversion
      type: text
      stored: false
      indexed: false
      description: "version information about the CloudEvents specification"
    - name: source
      type: text
      tokenizer: raw
      description: "information about where the event occurred"
    - name: subject
      type: text
      tokenizer: raw
      description: "detailed information about the source where the event occurred"
    - name: time
      type: datetime
      input_formats:
        - unix_timestamp
        - iso8601
      output_format: unix_timestamp_nanos
      fast: true
      description: "timestamp of the event"
    - name: datacontenttype
      type: text
      tokenizer: raw
      description: "content type of the data"
    - name: requestId
      type: text
      tokenizer: raw
      description: "request id"
    - name: ip
      type: ip
      fast: true
      description: "ip address"
    - name: userAgent
      type: text
      tokenizer: default
    - name: xUserAgent
      type: text
      tokenizer: default
    - name: userId
      type: text
      tokenizer: raw
    - name: deviceId
      type: text
      tokenizer: raw
      description: "device's id eg) 6ae1f6a6-107d-3183-a1df-adf7368f9d10"
    - name: latency
      type: text
      indexed: false
      stored: false
      description: "latency of the request, but already in latencyNs, so we don't need to index it"
    - name: latencyNs
      type: i64
      fast: true
      description: "latency of the request in nanoseconds"
    - name: occurredAt
      type: datetime
      input_formats:
        - unix_timestamp
        - iso8601
      output_format: unix_timestamp_nanos
      description: "timestamp of the log entry"
    - name: httpStatusCode
      type: i64
      fast: true
      description: "HTTP status code"
    - name: httpMethod
      type: text
      fast: true
      description: "HTTP method"
    - name: httpPath
      type: text
      fast: true
      description: "HTTP path"
    - name: grpcStatusCode
      type: i64
      fast: true
      description: "gRPC status code"
    - name: grpcMethod
      type: text
      fast: true
      description: "gRPC method"
    - name: extra
      type: json
      expand_dots: true
      description: "extra fields"
    - name: kafkaConsumerGroupId
      type: text
      fast: false
      description: "Kafka Consumer Group Id"
    - name: kafkaConsumerClientId
      type: text
      fast: false
      description: "Kafka Consumer Client Id"
    - name: kafkaConsumerHostName
      type: text
      fast: false
      description: "Kafka Consumer Host Name"
    - name: kafkaTopic
      type: text
      fast: false
      description: "Kafka Topic"
    - name: kafkaPartition
      type: i64
      description: "Kafka Partition"
    - name: kafkaOffset
      type: i64
      description: "Kafka Offset"
    - name: kafkaMessageKey
      type: text
      tokenizer: raw
      description: "Kafka Message Key"
    - name: kafkaConsumingResult
      type: text
      fast: true
      description: "Kafka Consuming Result"
    - name: env
      type: text
      tokenizer: raw
      indexed: true
      description: "represents environmental information as an extension field in the cloudEvents specification"
    - name: region
      type: text
      tokenizer: raw
      fast: true
      indexed: true
      description: "represents region information as an extension field in the cloudEvents specification"
    - name: namespace
      type: text
      tokenizer: raw
      fast: true
      indexed: true
      description: "represents namespace information as an extension field in the cloudEvents specification"
  timestamp_field: time
  tag_fields: [region]
  partition_key: namespace

search_settings:
    default_search_fields: [id, requestId, userId, extra.grpc.headers.x-request-id]

indexing_settings:
  merge_policy:
    type: "stable_log"
    merge_factor: 10
    max_merge_factor: 12
    maturation_period: 48h
  commit_timeout_secs: 30

retention:
  period: 30 days
  schedule: daily