Build: Blinded Coding Sheets

Maps to: Task 10. Kind: Build.

Objective

Create the panoptes-coding crate. Write make_sheet, which splits response records into a BlankSheetRow (opaque id + response text + empty code fields) and a separate KeyRow (the id→model/params mapping coders never see). Add the seeded shuffled_indices. Prove the sheet leaks nothing.

Scaffold

Create (new crate — add it to workspace members):

• crates/panoptes-coding/Cargo.toml — [dependencies]: panoptes-core = { path = "../panoptes-core" }, plus serde, serde_json, thiserror, clap, anyhow (all { workspace = true }); [dev-dependencies]: tempfile = "3". (thiserror is for the next chapter's error type — the original task plan omits it, so declare it now.)
• crates/panoptes-coding/src/lib.rs and src/sheets.rs.

Expected result: cargo test -p panoptes-coding sheets → 2 tests pass (sheet_does_not_leak_identity, shuffle_is_deterministic_and_a_permutation).

The spec (givens)

• BlankSheetRow fields (all String, code fields empty in the blank): response_id, response, c1_action, c2_logic, c2_anchor_quote, c3_escalation, codebook_version, coder_notes. Derives: Debug, Clone, Serialize.
• KeyRow fields: response_id: String, vignette_id: String, model: String, epoch: u32 — the mapping coders never see.
• make_sheet(records: &[ResponseRecord]) -> (Vec<BlankSheetRow>, Vec<KeyRow>).
• shuffled_indices(n: usize, seed: u64) -> Vec<usize>: Fisher–Yates driven by a small inline LCG (constants in the Answer Key) — deterministic per seed, no rand dependency.

Full code: Answer Key, Task 10.

Concepts exercised

• Splitting one record into two types by what each audience may see.
• A seeded permutation without an external rand dependency (a small LCG).
• The blinding invariant as a test.

The build loop (you drive)

1. Write failing tests: sheet_does_not_leak_identity (serialized sheet contains no model name, no vignette id, no parameters, but the key retains them); shuffle_is_deterministic_and_a_permutation.
2. Predict: the leak test serializes the sheet to JSON and asserts the string does not contain "claude". What field on BlankSheetRow would make this test fail, and why is its absence the whole point?
3. Run, check.
4. Implement.
5. Run green, commit.

Done when

cargo test -p panoptes-coding sheets passes. The blinding property is now guaranteed by the type, not by your memory.