# per_aggregate_dataclass_promotion

## v1

**Why this iteration:** Lifted from `conductor/code_styleguides/type_aliases.md` §2.5 — the per-aggregate promotion rule codifies that any sub-aggregate with stable distinct fields must be its OWN `@dataclass(frozen=True, slots=True)`, not a shared mega-dataclass.
**Source:** `conductor/code_styleguides/type_aliases.md` §2.5 ("When the role has stable distinct fields, promote it to its OWN dataclass")

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**Lifted:** 2026-07-03 scavenge sweep batch 4/5: tracks + commands + styleguides + todos