ZIm/crates/eval/examples/lhs_join_update_callbacks/prompt.md

Add a new test case to validate join subscription updates when the LHS table is updated, and ensure correct invocation of reducer callbacks. The test should:

• Subscribe to a join query with a filter involving fields from both tables (e.g., SELECT p.* FROM pk_u32 p JOIN unique_u32 u ON p.n = u.n WHERE u.data > 0 AND u.data < 5).
• Insert rows into both LHS (pk_u32) and RHS (unique_u32) that satisfy the join condition.
• Verify the initial subscription callback is triggered via on_insert.
• Update the LHS (pk_u32) such that the row remains part of the join result.
• Validate that:
  • on_update is invoked correctly.
  • An immediate follow-up update back to the original value also triggers on_update.
• Repeat the above with disjoint filters (e.g., u.n != 1) and confirm behavior remains correct.

Also, ensure that literal-first SQL expressions like 3 < x are correctly interpreted and inverted in the physical execution plan (converted to x > 3) and behave identically during query evaluation and execution.