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+# Strategic Design
+
+Use this branch when the user asks where to invest modeling effort or whether to build, reuse, or buy a capability.
+
+## Classify by the actual business
+
+- **Core:** the behavior that provides the product's distinctive value.
+- **Supporting:** business-specific functionality needed to deliver that value.
+- **Generic:** a broadly shared problem where existing solutions may fit.
+
+These are decision aids, not fixed quality tiers or staffing rules. Security, accessibility, and data integrity remain required in every category. A domain's classification can change as the product changes.
+
+## Compare concrete options
+
+Start with the existing implementation and stack. Compare options against needed behavior, integration cost, operational burden, lock-in, privacy/security constraints, and available expertise.
+
+Do not prescribe a vendor, dependency, outsourcing arrangement, or percentage allocation from a generic example. Verify current primary sources before making a real product recommendation and preserve the user's selected product unless changing it is in scope.
+
+## Distill the decision
+
+Identify the concepts and invariants that deserve the most attention, the surrounding functionality that can stay simple, and the evidence supporting that choice. Update existing domain documents only when requested; propose an ADR for a consequential, non-obvious trade-off rather than creating a parallel architecture handbook.
+
+End with a focused recommendation and its limitations. A strategy discussion does not authorize purchasing services, provisioning infrastructure, or reorganizing the codebase.