diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
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+# PowerToys – Copilot guide (concise)
+
+This is the top-level guide for AI changes. Keep edits small, follow existing patterns, and cite exact paths in PRs.
+
+Repo map (1‑line per area)
+- Core apps: `src/runner/**` (tray/loader), `src/settings-ui/**` (Settings app)
+- Shared libs: `src/common/**`
+- Modules: `src/modules/*` (one per utility; Command Palette in `src/modules/cmdpal/**`)
+- Build tools/docs: `tools/**`, `doc/devdocs/**`
+
+Build and test (defaults)
+- Prerequisites: Visual Studio 2022 17.4+, minimal Windows 10 1803+.
+- Build discipline:
+  - One terminal per operation (build → test). Don’t switch/open new ones mid-flow.
+  - After making changes, `cd` to the project folder that changed (`.csproj`/`.vcxproj`).
+  - Use script(s) to build, synchronously block and wait in foreground for it to finish: `tools/build/build.ps1|.cmd` (current folder), `build-essentials.*` (once per brand new build for missing nuget packages)
+  - Treat build **exit code 0** as success; any non-zero exit code is a failure, have Copilot read the errors log in the build folder (e.g., `build.*.*.errors.log`) and surface problems.
+  - Don’t start tests or launch Runner until the previous step succeeded.
+- Tests (fast + targeted):
+  - Find the test project by product code prefix (e.g., FancyZones, AdvancedPaste). Look for a sibling folder or 1–2 levels up named like `<Product>*UnitTests` or `<Product>*UITests`.
+  - Build the test project, wait for **exit**, then run only those tests via VS Test Explorer or `vstest.console.exe` with filters. Avoid `dotnet test` in this repo.
+  - Add/adjust tests when changing behavior; if skipped, state why (e.g., comment-only, string rename).
+
+Pull requests (expectations)
+- Atomic: one logical change; no drive‑by refactors.
+- Describe: problem / approach / risk / test evidence.
+- List: touched paths if not obvious.
+
+When to ask for clarification
+- Ambiguous spec after scanning relevant docs (see below).
+- Cross-module impact (shared enum/struct) not clear.
+- Security / elevation / installer changes.
+
+Logging (use existing stacks)
+- C++: `src/common/logger/**` (`Logger::info|warn|error|debug`). Keep hot paths quiet (hooks, tight loops).
+- C#: `ManagedCommon.Logger` (`LogInfo|LogWarning|LogError|LogDebug|LogTrace`). Some UIs use injected `ILogger` via `LoggerInstance.Logger`.
+
+Docs to consult
+- `tools/build/BUILD-GUIDELINES.md`
+- `doc/devdocs/core/architecture.md`, `doc/devdocs/core/runner.md`, `doc/devdocs/core/settings/readme.md`, `doc/devdocs/modules/readme.md`
+
+Done checklist (self review before finishing)
+- Build clean? Tests updated/passed? No unintended formatting? Any new dependency? Documented skips?
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diff --git a/src/common/common.instructions.md b/src/common/common.instructions.md
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+---
+applyTo: "**/*.cs,**/*.cpp,**/*.c,**/*.h,**/*.hpp"
+---
+# Common – shared libraries guidance (concise)
+
+Scope
+- Logging, IPC, settings, DPI, telemetry, utilities consumed by multiple modules.
+
+Guidelines
+- Avoid breaking public headers/APIs; if changed, search & update all callers.
+- Coordinate ABI-impacting struct/class layout changes; keep binary compatibility.
+- Watch perf in hot paths (hooks, timers, serialization); avoid avoidable allocations.
+- Ask before adding third‑party deps or changing serialization formats.
+
+Acceptance
+- No unintended ABI breaks, no noisy logs, new non-obvious symbols briefly commented.
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diff --git a/src/runner/runner.instructions.md b/src/runner/runner.instructions.md
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+---
+applyTo: "**/*.cpp,**/*.c,**/*.h,**/*.hpp,**/*.rc"
+---
+# Runner – tray / host process guidance
+
+Scope
+- Module bootstrap, hotkey management, settings bridge, update/elevation handling.
+
+Guidelines
+- If IPC/JSON contracts change, mirror updates in `src/settings-ui/**`.
+- Keep module discovery in `src/runner/main.cpp` in sync when adding/removing modules.
+- Keep startup lean: avoid blocking/network calls in early init path.
+- Preserve GPO & elevation behaviors; confirm no regression in policy handling.
+- Ask before modifying update workflow or elevation logic.
+
+Acceptance
+- Stable startup, consistent contracts, no unnecessary logging noise.
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diff --git a/src/settings-ui/settings-ui.instructions.md b/src/settings-ui/settings-ui.instructions.md
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+---
+applyTo: "**/*.cs,**/*.xaml"
+---
+# Settings UI – configuration app guidance
+
+Scope
+- WinUI/WPF UI, communicates with Runner over named pipes; manages persisted settings schema.
+
+Guidelines
+- Don’t break settings schema silently; add migration when shape changes.
+- If IPC/JSON contracts change, align with `src/runner/**` implementation.
+- Keep UI responsive: marshal to UI thread for UI-bound operations.
+- Reuse existing styles/resources; avoid duplicate theme keys.
+- Add/adjust migration or serialization tests when changing persisted settings.
+
+Acceptance
+- Schema integrity preserved, responsive UI, consistent contracts, no style duplication.
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