Module fields 

Single source of truth for the set of displayable fields and their output strata.

Historically the field list was hand-duplicated across main.rs (collection allow-lists and the generated config template), display.rs (display allow-lists), config.rs (DEFAULT_FIELDS_BLOCK), plus README.md and docs/retch.1.md. Every copy was a raw list of &str literals with no shared definition, so adding or renaming a field risked silent drift — a field could be collected but never displayed (or vice versa), or documented inconsistently.

This module replaces the in-code copies with one [FIELDS] table. main.rs and display.rs derive their per-strata allow-lists from fields_for, and both config-generation paths derive the commented fields = [...] block from config_fields_block. The documentation copies (README.md, docs/retch.1.md) can’t be generated from Rust, so a guardrail test in tests/cli_tests.rs asserts every [FIELDS] key appears in both, turning future drift into a test failure instead of a silent bug.

Enums

Mode

Output verbosity mode, ordered from least to most verbose.

Functions

all_keys

Returns every field key, in table order.

config_fields_block

Generates the commented fields = [...] block for the default config file.

fields_for

Returns the ordered list of field keys visible in the given Mode.