feat: add winmd-api-search skill for Windows desktop API discovery

docs/README.skills.md

@@ -227,5 +227,6 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-skills) for guidelines on how to
 | [webapp-testing](../skills/webapp-testing/SKILL.md) | Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs. | `test-helper.js` |
 | [what-context-needed](../skills/what-context-needed/SKILL.md) | Ask Copilot what files it needs to see before answering a question | None |
 | [winapp-cli](../skills/winapp-cli/SKILL.md) | Windows App Development CLI (winapp) for building, packaging, and deploying Windows applications. Use when asked to initialize Windows app projects, create MSIX packages, generate AppxManifest.xml, manage development certificates, add package identity for debugging, sign packages, publish to the Microsoft Store, create external catalogs, or access Windows SDK build tools. Supports .NET (csproj), C++, Electron, Rust, Tauri, and cross-platform frameworks targeting Windows. | None |
+| [winmd-api-search](../skills/winmd-api-search/SKILL.md) | Find and explore Windows desktop APIs. Use when building features that need platform capabilities — camera, file access, notifications, UI controls, AI/ML, sensors, networking, etc. Discovers the right API for a task and retrieves full type details (methods, properties, events, enumeration values). | `LICENSE.txt`<br />`scripts/Invoke-WinMdQuery.ps1`<br />`scripts/Update-WinMdCache.ps1`<br />`scripts/cache-generator/CacheGenerator.csproj`<br />`scripts/cache-generator/Directory.Build.props`<br />`scripts/cache-generator/Directory.Build.targets`<br />`scripts/cache-generator/Directory.Packages.props`<br />`scripts/cache-generator/Program.cs` |
 | [workiq-copilot](../skills/workiq-copilot/SKILL.md) | Guides the Copilot CLI on how to use the WorkIQ CLI/MCP server to query Microsoft 365 Copilot data (emails, meetings, docs, Teams, people) for live context, summaries, and recommendations. | None |
 | [write-coding-standards-from-file](../skills/write-coding-standards-from-file/SKILL.md) | Write a coding standards document for a project using the coding styles from the file(s) and/or folder(s) passed as arguments in the prompt. | None |

skills/winmd-api-search/LICENSE.txt

@@ -0,0 +1,21 @@
+The MIT License
+
+Copyright (c) Microsoft Corporation. All rights reserved.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.

skills/winmd-api-search/SKILL.md

@@ -0,0 +1,187 @@
+---
+name: winmd-api-search
+description: 'Find and explore Windows desktop APIs. Use when building features that need platform capabilities — camera, file access, notifications, UI controls, AI/ML, sensors, networking, etc. Discovers the right API for a task and retrieves full type details (methods, properties, events, enumeration values).'
+license: Complete terms in LICENSE.txt
+---
+
+# WinMD API Search
+
+This skill helps you find the right Windows API for any capability and get its full details. It searches a local cache of all WinMD metadata from:
+
+- **Windows Platform SDK** — all `Windows.*` WinRT APIs (always available, no restore needed)
+- **WinAppSDK / WinUI** — bundled as a baseline in the cache generator (always available, no restore needed)
+- **NuGet packages** — any additional packages in restored projects that contain `.winmd` files
+- **Project-output WinMD** — class libraries (C++/WinRT, C#) that produce `.winmd` as build output
+
+Even on a fresh clone with no restore or build, you still get full Platform SDK + WinAppSDK coverage.
+
+## When to Use This Skill
+
+- User wants to build a feature and you need to find which API provides that capability
+- User asks "how do I do X?" where X involves a platform feature (camera, files, notifications, sensors, AI, etc.)
+- You need the exact methods, properties, events, or enumeration values of a type before writing code
+- You're unsure which control, class, or interface to use for a UI or system task
+
+## Prerequisites
+
+- **.NET SDK 8.0 or later** — required to build the cache generator. Install from [dotnet.microsoft.com](https://dotnet.microsoft.com/download) if not available.
+
+## Cache Setup (Required Before First Use)
+
+All query and search commands read from a local JSON cache. **You must generate the cache before running any queries.**
+
+```powershell
+# All projects in the repo (recommended for first run)
+.\.github\skills\winmd-api-search\scripts\Update-WinMdCache.ps1
+
+# Single project
+.\.github\skills\winmd-api-search\scripts\Update-WinMdCache.ps1 -ProjectDir <project-folder>
+```
+
+No project restore or build is needed for baseline coverage (Platform SDK + WinAppSDK). For additional NuGet packages, the project needs `dotnet restore` (which generates `project.assets.json`) or a `packages.config` file.
+
+Cache is stored at `Generated Files\winmd-cache\`, deduplicated per-package+version.
+
+### What gets indexed
+
+| Source | When available |
+|--------|----------------|
+| Windows Platform SDK | Always (reads from local SDK install) |
+| WinAppSDK (latest) | Always (bundled as baseline in cache generator) |
+| Project NuGet packages | After `dotnet restore` or with `packages.config` |
+| Project-output `.winmd` | After project build (class libraries that produce WinMD) |
+
+> **Note:** This cache directory should be in `.gitignore` — it's generated, not source.
+
+## How to Use
+
+Pick the path that matches the situation:
+
+---
+
+### Discover — "I don't know which API to use"
+
+The user describes a capability in their own words. You need to find the right API.
+
+**0. Ensure the cache exists**
+
+If the cache hasn't been generated yet, run `Update-WinMdCache.ps1` first — see [Cache Setup](#cache-setup-required-before-first-use) above.
+
+**1. Translate user language → search keywords**
+
+Map the user's daily language to programming terms. Try multiple variations:
+
+| User says | Search keywords to try (in order) |
+|-----------|-----------------------------------|
+| "take a picture" | `camera`, `capture`, `photo`, `MediaCapture` |
+| "load from disk" | `file open`, `picker`, `FileOpen`, `StorageFile` |
+| "describe what's in it" | `image description`, `Vision`, `Recognition` |
+| "show a popup" | `dialog`, `flyout`, `popup`, `ContentDialog` |
+| "drag and drop" | `drag`, `drop`, `DragDrop` |
+| "save settings" | `settings`, `ApplicationData`, `LocalSettings` |
+
+Start with simple everyday words. If results are weak or irrelevant, try the more technical variation.
+
+**2. Run searches**
+
+```powershell
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action search -Query "<keyword>"
+```
+
+This returns ranked namespaces with top matching types and the **JSON file path**.
+
+If results have **low scores (below 60) or are irrelevant**, fall back to searching online documentation:
+
+1. Use web search to find the right API on Microsoft Learn, for example:
+   - `site:learn.microsoft.com/en-us/uwp/api <capability keywords>` for `Windows.*` APIs
+   - `site:learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt <capability keywords>` for `Microsoft.*` WinAppSDK APIs
+2. Read the documentation pages to identify which type matches the user's requirement.
+3. Once you know the type name, come back and use `-Action members` or `-Action enums` to get the exact local signatures.
+
+**3. Read the JSON to choose the right API**
+
+Read the file at the path(s) from the top results. The JSON has all types in that namespace — full members, signatures, parameters, return types, enumeration values.
+
+Read and decide which types and members fit the user's requirement.
+
+**4. Look up official documentation for context**
+
+The cache contains only signatures — no descriptions or usage guidance. For explanations, examples, and remarks, look up the type on Microsoft Learn:
+
+| Namespace prefix | Documentation base URL |
+|-----------------|----------------------|
+| `Windows.*` | `https://learn.microsoft.com/en-us/uwp/api/{fully.qualified.typename}` |
+| `Microsoft.*` (WinAppSDK) | `https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/{fully.qualified.typename}` |
+
+For example, `Microsoft.UI.Xaml.Controls.NavigationView` maps to:
+`https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/microsoft.ui.xaml.controls.navigationview`
+
+**5. Use the API knowledge to answer or write code**
+
+---
+
+### Lookup — "I know the API, show me the details"
+
+You already know (or suspect) the type or namespace name. Go direct:
+
+```powershell
+# Get all members of a known type
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action members -TypeName "Microsoft.UI.Xaml.Controls.NavigationView"
+
+# Get enum values
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action enums -TypeName "Microsoft.UI.Xaml.Visibility"
+
+# List all types in a namespace
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action types -Namespace "Microsoft.UI.Xaml.Controls"
+
+# Browse namespaces
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action namespaces -Filter "Microsoft.UI"
+```
+
+If you need full detail beyond what `-Action members` shows, use `-Action search` to get the JSON file path, then read the JSON file directly.
+
+---
+
+### Other Commands
+
+```powershell
+# List cached projects
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action projects
+
+# Show stats
+.\.github\skills\winmd-api-search\scripts\Invoke-WinMdQuery.ps1 -Action stats
+```
+
+> If only one project is cached, `-Project` is auto-selected.
+> If multiple projects exist, add `-Project <name>`.
+
+## Search Scoring
+
+The search ranks type names against your query:
+
+| Score | Match type | Example |
+|-------|-----------|---------|
+| 100 | Exact name | `Button` → `Button` |
+| 80 | Starts with | `Navigation` → `NavigationView` |
+| 60 | Contains | `Dialog` → `ContentDialog` |
+| 50 | PascalCase initials | `ASB` → `AutoSuggestBox` |
+| 40 | Multi-keyword AND | `navigation item` → `NavigationViewItem` |
+| 20 | Fuzzy character match | `NavVw` → `NavigationView` |
+
+Results are grouped by namespace. Higher-scored namespaces appear first.
+
+## Troubleshooting
+
+| Issue | Fix |
+|-------|-----|
+| "Cache not found" | Run `Update-WinMdCache.ps1` |
+| "Multiple projects cached" | Add `-Project <name>` |
+| "Namespace not found" | Use `-Action namespaces` to list available ones |
+| "Type not found" | Use fully qualified name (e.g., `Microsoft.UI.Xaml.Controls.Button`) |
+| Stale after NuGet update | Re-run `Update-WinMdCache.ps1` |
+| Cache in git history | Add `Generated Files/` to `.gitignore` |
+
+## References
+
+- [Windows Platform SDK API reference](https://learn.microsoft.com/en-us/uwp/api/) — documentation for `Windows.*` namespaces
+- [Windows App SDK API reference](https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/) — documentation for `Microsoft.*` WinAppSDK namespaces