qstack-model-the-domainlisted

# Model the domain Encode the real domain in a structure instead of distributing it across booleans, conditionals, loose parameters, and lifecycle checks. ## Find the missing shape 1. Trace the states, transitions, invariants, ownership, and dominant access paths in the current code. 2. Locate repeated shape assumptions, synchronized booleans, growing branches, ad hoc mutation, and phase-named modules that repeat the same domain rules. 3. Choose the smallest structure that removes those problems. Candidates include a state machine, typed model, discriminated union, registry, lookup table, reducer, command/event model, queue, cache, index, graph, normalized collection, or one module that owns a coherent body of domain knowledge. 4. Compare the proposed shape with the current one. It must delete branches, duplicated rules, invalid states, or lifecycle risk. Extra indirection alone is not a benefit. 5. Leave clear, local, stable code alone when no structure materially improves it. Three explicit statements can be better than a premature abstraction. State the invariant the model enforces, the access patterns it serves, the invalid states it removes, and the migration boundary. Design work does not authorize implementation beyond the user's request. Assess compatibility and migration before changing a public API or persisted shape. Design alone does not authorize commits, pushes, publishing, deployment, or external messages. Adapted from Lauren Tan's