Code health: executor_dst.rs exceeds 500-line limit (2449 lines)

[nerdsane]

Context

Found during code review of bitmap implementation (commit e9be18b).

Problem

src/redis/executor_dst.rs is 2449 lines — nearly 5x the project's 500-line guideline. This is pre-existing technical debt. The file is not documented in docs/adr/gaps/ as a known deviation.

Suggested Fix

Split into category-specific modules similar to the executor itself:

• executor_dst/mod.rs — harness core, shadow state, assertions
• executor_dst/string_ops.rs — string op DST (including bitmap)
• executor_dst/key_ops.rs — key op DST
• executor_dst/list_ops.rs, set_ops.rs, hash_ops.rs, sorted_set_ops.rs, expiry_ops.rs

Alternatively, document the deviation in docs/adr/gaps/.

Severity

Low — maintainability concern, not a correctness issue.

Found By

Rust-dev review agent (Finding 5)