docs: add release notes and docs for batched shuffle insertion (PR #1369) - #1698

Greptile Summary

This PR adds release notes and documentation for the batched shuffle insertion feature (identification_batchsize) introduced in PR #1369 for ExactDeduplicationWorkflow. The changes are purely documentation — two MDX files are updated to describe the new parameter, its performance trade-offs, and revised best practices for block sizing.

• Adds a new ## Improvements section to the v26.04 release notes describing the identification_batchsize parameter and the batch-aware shuffle adapter fallback behavior.
• Adds identification_batchsize to the configuration reference table in exact.mdx with type, default, and description.
• Updates the performance best-practices bullet in exact.mdx to recommend smaller input_blocksize values paired with a larger identification_batchsize (targeting 2–6 GB per insertion call) instead of the previous 2GiB default recommendation.
• The two identification_batchsize examples used within exact.mdx (value 4 in the table, value 8 in best practices) are mathematically consistent but point readers at different starting points, which could create confusion.

Confidence Score: 5/5

Documentation-only PR with no code changes; safe to merge.

All findings are P2 style/consistency suggestions. There are no logic errors, broken links, incorrect parameter descriptions, or code changes of any kind. The documentation accurately describes the feature and its trade-offs.

No files require special attention; minor example-value alignment between the config table and best-practices bullet in exact.mdx would improve clarity.

Important Files Changed

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    A[ExactDeduplicationWorkflow] -->|reads blocks of input_blocksize| B[Input Blocks]
    B -->|batched by identification_batchsize| C{Batch Ready?}
    C -->|No — accumulate more blocks| B
    C -->|Yes — batch full| D[Concatenate Blocks into Batch]
    D --> E{Stage has read_and_insert_batch?}
    E -->|Yes| F[read_and_insert_batch\nbatch-aware path]
    E -->|No — fallback| G[Single-task insertion]
    F --> H[Shuffler / GPU Operations]
    G --> H
    H --> I[ExactDuplicateIds output]

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