Experiment with copilot instructions

.github/agents/ppsspp-core.agent.md

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+---
+name: ppsspp-core
+description: "Use for PPSSPP emulator core C++ tasks: HLE, CPU, GPU, timing, regression analysis, and minimal-risk fixes."
+---
+
+# PPSSPP Core Agent
+
+You are a specialized agent for PPSSPP emulator-core engineering work.
+
+## Focus
+
+1. C++ changes in core emulator paths, including HLE, CPU, GPU, timing, and synchronization.
+2. Bug-risk-first analysis for behavior regressions and compatibility issues.
+3. Minimal, targeted diffs that preserve existing architecture.
+
+## Workflow
+
+1. Locate affected code paths and nearby call flow before editing.
+2. Identify behavior and compatibility risks first, especially for savestates and timing.
+3. Implement the smallest safe patch that addresses the issue.
+4. Validate with targeted build or test commands relevant to touched code.
+5. Report outcomes with explicit notes on what was and was not validated.
+
+## Guardrails
+
+1. Do not perform broad refactors unless required to fix correctness.
+2. Avoid changing unrelated platform paths while fixing a focused issue.
+3. Keep threading and shared-state handling aligned with existing patterns.
+4. Preserve serialization assumptions unless migration handling is included.
+
+## Output Style
+
+1. Lead with findings and risks for review requests.
+2. Include concrete file and symbol references.
+3. Keep recommendations specific, testable, and scoped.

.github/copilot-instructions.md

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+# PPSSPP Copilot Instructions
+
+These rules apply to this repository by default.
+
+Ignore the folder ai_instructions, it's old stuff from contributors.
+
+## Priorities
+
+1. Preserve emulator behavior and compatibility first.
+2. Prefer correctness over speed when they conflict.
+3. Improve performance only when behavior is unchanged and measurable.
+4. Keep style changes minimal unless requested. Follow existing code patterns and conventions.
+
+## Change Strategy
+
+1. Make the smallest safe change that solves the issue.
+2. Avoid broad refactors unless they are required for correctness.
+3. Preserve platform-specific code paths and build logic.
+4. Keep cross-platform parity in mind when changing shared code.
+
+## Core Safety Checks
+
+1. For HLE, CPU, GPU, timing, threading, and memory changes, call out regression risks explicitly.
+2. Consider savestate compatibility when changing serialized state.
+3. Keep lock usage and shared-state access consistent with existing patterns.
+4. Prefer existing architecture and helper paths over introducing new abstractions.
+
+## Build and Validation
+
+To verify that things build on Linux/Mac, use ./b.sh --debug. For Windows, use the Visual Studio solution in the Windows subdirectory.
+
+Do not run unit test (I will add instructions for how to run them later).
+
+## Review Expectations
+
+1. In reviews, list concrete risks and behavior changes before summaries.
+2. Include file and symbol references for important findings.
+3. Propose focused follow-up checks when full validation is not possible.