[ARCH-11] `crates/state/src/tests.rs` is 3,726 LOC — single-file monolith, 44% of the crate

[intendednull]

Commit: 2f26d91 · Finding: ARCH-11

Problem

crates/state/src/tests.rs:1-3726 is a 3.7k-line single-file test module — 1.5× the size of materialize.rs (1,363 lines) and the largest file in the crate. Adding a new #[test] requires navigating the monolith.

Fix

Split by concern:

• crates/state/src/tests/permissions.rs
• crates/state/src/tests/dag.rs
• crates/state/src/tests/materialize.rs
• crates/state/src/tests/sync.rs
• crates/state/src/tests/voting.rs

Use the #[path = "tests/..."] pattern already established in crates/client/src/lib.rs:49-55.

Obvious fix — mechanical split. Will be auto-PR'd.