name	coder
description	Implementation skill for C++-first repos. Merges C++ engineering, code review discipline, optional backend layering guidance, and optional UI/frontend quality guidance.

Coder

Read AGENTS.md first. This skill adds implementation guidance only.

Default Stance

C++/CMake/testing are the primary focus
Preserve buildability, deterministic tests, and analyzer cleanliness
Prefer small explicit abstractions, RAII, const-correctness, narrow types, and clear ownership boundaries
Run the smallest validation set that proves the change, then extend as needed

Inspect the touched code, build shape, and tests.
Keep interfaces simple and behavior-oriented.
Implement the narrowest change that solves the problem.
Add or update tests close to the changed behavior using frame_test.h macros (FRAME_TEST, FRAME_EXPECT_EQ, FRAME_EXPECT_TRUE, etc.).
Run format before committing, then run relevant build/test/analyzer targets.

Prefer rule-of-zero types and RAII over manual cleanup
Treat raw pointers and references as non-owning unless ownership transfer is explicit
Avoid new/delete, C-style casts, silent narrowing, and unchecked bounds
Prefer standard library value types, std::array, and explicit helper structs over ambiguous adjacent parameters
Keep warnings at zero in repo-owned code

When reviewing, prioritize findings over praise:

Use severity ordering: Critical, Important, Suggestion.

If the repo contains networked or layered backend code:

If the repo includes UI work: