Update changelog for v4.106.0

[github-actions]

Added

• salesforce_cdc: Added decode-failure bounds and classification of schema-fetch errors (deterministic vs transient) to prevent infinite retry loops and livelocks, with terminal failures surfaced clearly to the health check. (@squiidz, #4689)

Fixed

• aws_dynamodb_cdc: Fixed silent data loss in snapshot handling by gating checkpoint persistence on downstream acknowledgments, ensuring rejected batches are redelivered instead of skipped. (@squiidz, #4687)
• aws_dynamodb_cdc: Fixed stream rotation and restart scenarios where start_from: latest was incorrectly applied to child shards and checkpoint-less shards discovered after initial setup, causing silent loss of backlog. (@squiidz, #4687)
• cockroachdb_changefeed: Fixed unbounded silent data loss where transaction rows and backfill batches sharing timestamps could skip data on restart; now checkpoints only persist resolved timestamps to guarantee no loss. (@squiidz, #4688)
• salesforce_cdc: Fixed multiple silent-loss paths in Pub/Sub gRPC handling and ack functions: full buffer now applies backpressure instead of dropping events, schema/decode failures reconnect without losing batches, and nacks now pin checkpoints. (@squiidz, #4689)
• salesforce_cdc: Fixed off-by-one error in schema-retry budgeting and credential refresh in unanchored schema retries to prevent indefinite stalls under the default unlimited reconnect policy. (@squiidz, #4689)

Changed

• aws_dynamodb_cdc: Added auto_replay_nacks support to automatically retry transient downstream failures in-process, with nacks now advancing checkpoints when auto_replay_nacks is disabled. (@squiidz, #4687)
• cockroachdb_changefeed: Changed nack handling to advance cursors when auto_replay_nacks is disabled, treating it as an opt-in to drop rejected messages per the framework contract. (@squiidz, #4688)
• general: Updated CDC connector documentation across Microsoft SQL Server, MongoDB, and OracleDB with measured performance characteristics, scaling limitations, and configuration guidance based on real-world benchmarking. (@prakhargarg105, #4691)