Add model selection rule for Claude Code
Assisted-by: Claude Opus 4.6 via pi
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+# Model Selection
+
+Default to Opus for interactive sessions. Drop down when the task is
+clearly mechanical.
+
+## Opus
+
+The default. Interactive coding, reasoning, architecture decisions,
+multi-file refactors, debugging, writing, code review — anything
+involving judgment or conversation.
+
+## Sonnet
+
+Subagents, background tasks, well-scoped autonomous work where the
+instructions are clear and the task is bounded.
+
+## Haiku
+
+Commit messages, simple lookups, formatting, mechanical edits, generating
+boilerplate. Anywhere speed matters more than depth.