mayhem-firmware Agent Skills & AI Rules

# Copilot Pull Request Review Instructions

These instructions define how to review pull requests for the PortaPack Mayhem firmware (an embedded, resource-constrained, dual-core ARM Cortex-M0/M4 project). They complement `AGENT.md`.

## 1. Understand the stated goal

Before reviewing any code, answer these questions from the PR title, description and diff:

- What does the PR claim to add or fix?
- Does the diff address that stated goal? Identify concrete gaps between the claim and implementation.

## 2. Minimal, focused changes

- The diff must be as small as possible and address a single purpose.
- Flag unrelated refactors, reformatting, renames, or drive-by fixes (scope creep).
- Question Python tests or other test code that is not relevant to the change or does not fit the project's existing validation setup.
- Flag unrelated Markdown, documentation, and other non-code files; include them only when they directly support the change.
- Flag new `std::` facilities that are not already established in the project or relevant code area; do not object to existing usage, including `std::string`, solely because it is from the standard library.
- Prefer existing project patterns and helpers over new ones.

## 3. Hardware constraints

- RAM and flash are very limited. Flag dynamic allocation, large stack or static buffers, and unneeded copies.
- The firmware is dual-core (M0 application, M4 baseband). Check that code runs on the correct core and that shared memory and IPC messages are used safely (message sizes, ordering, no blocking in baseband/interrupt context, no unsynchronized shared state).
- External apps and baseband images must fit their memory regions.
- Baseband/DSP code must stay deterministic and fast.

## 4. Hardware verification

- Changes touching radio, baseband, peripherals, or timing must state how they were tested on real hardware (board model, firmware build).
- If the PR does not say it was tested, or only claims it "should work", ask for explicit verification.

## 5. Code quality (within project norms)

- Follow the existing style and naming of surrounding code.
- Check for undefined behavior, integer overflow, buffer bounds, uninitialized variables, and unsafe casts.
- Check that new UI strings, app IDs, and message IDs follow existing conventions and remain unique/consecutive where required.

## 6. Red flags (recommend rejection or major rework)

- The problem is not real, or the change rests on a misunderstanding.
- Large diffs for small problems; unrelated changes mixed in.
- Introduces dynamic memory without strong justification.
- Unsafe cross-core/IPC access.
- Claims of hardware behavior with no verification.