Remove legacy WPF app, flatten WinUI project to repo root, rename namespace

The repo carried two parallel UIs (WPF + WinUI) sharing Models/Services via
cross-directory Link includes. Now that WinUI is the only frontend, collapse
the structure so the WinUI project IS the repo root instead of a nested
sibling folder:

- Delete the WPF project entirely (App.xaml, MainWindow.xaml, csproj) and its
  bin/obj output
- Move AmiReel.WinUI/* up to the repo root (App, MainWindow, MainPage,
  DialogHelper, Assets, Package.appxmanifest, app.manifest, Properties,
  .github/instructions, AGENTS.md) via git mv, preserving history
- Rename AmiReel.WinUI.csproj -> AmiReel.csproj; regenerate the solution as
  AmiReel.slnx (the newer XML solution format) with a single project
- Rename namespace AmigaDB.VideoRenderer.{Models,Services} -> AmiReel.{...}
  and AmiReel_WinUI -> AmiReel across all files, including the embedded
  ffmpeg/ffprobe resource logical names in the csproj and ToolExtractor
- Models/ and Services/ no longer need the Link-based cross-directory
  <Compile Include>; they're picked up by the SDK's default globbing now
  that they live under the project directory
- Rename assets/ -> branding/ (source icon art) to avoid a case-insensitive
  collision with Assets/ (packaged tile art) once both sit at repo root
- Merge the two .gitignore files into one; track the PublishProfiles pubxml
  files instead of ignoring them (no secrets, and they keep publish
  reproducible across machines) as branding, gitignore, etc.
- Simplify publish-win-x64.ps1 (drop the -Target Wpf/WinUI switch, there's
  only one target now) and rewrite README.md to describe the single-project
  layout, build/run/publish commands, and file structure

Verified: dotnet build succeeds for both AmiReel.csproj and AmiReel.slnx, and
the built exe launches and renders identically to before the move.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.github/instructions/windows-apis.instructions.md

@@ -0,0 +1,92 @@
+---
+description: 'WinAppSDK & Windows Platform SDK -- API namespace catalog and lookup guidance'
+applyTo: '**/*.cs, **/*.xaml, **/*.csproj'
+---
+
+# Windows APIs -- WinAppSDK & Windows Platform SDK
+
+## Sample-First Rule
+
+> **Agent Rule -- MANDATORY:** Before implementing **any** WinAppSDK or Windows Platform SDK API you have not used before, you **must** search the sample repositories below for a working example first. **Do not guess API usage patterns from documentation alone** -- the docs often omit critical details that only the sample code reveals. Search **all** of the following repos, not just one:
+
+| # | Repository | What it covers |
+|---|---|---|
+| 1 | [WindowsAppSDK-Samples](https://github.com/microsoft/WindowsAppSDK-Samples) | All WinAppSDK features (AI, windowing, lifecycle, notifications, etc.) |
+| 2 | [AI Dev Gallery](https://github.com/microsoft/ai-dev-gallery) | On-device AI/ML patterns, model usage examples |
+| 3 | [WinUI-Gallery](https://github.com/microsoft/WinUI-Gallery) | UI control patterns and XAML examples |
+
+### How to apply
+
+1. **Find the right API** -- Translate the user's scenario/requirement into common API/programming keywords, then search the API references (Part A-B below) using those keywords to identify which API fits.
+2. **Search for samples** -- Once you know which API to use, search each sample repo above for the class name to find a working example.
+3. **Study the sample** -- Read the sample's Model / ViewModel / Service layer to understand how the API is actually called -- object lifetime, required parameters, data preparation, error handling.
+4. **Adapt** the sample pattern into our MVVM architecture -- don't copy the sample structure wholesale, but match its API call sequence exactly.
+
+---
+
+> **Agent Rule:** Before implementing any feature that involves a platform capability, **consult this file** to check whether a built-in API already exists. Always verify exact class names, method signatures, and availability by following the reference links -- do not guess API shapes.
+
+---
+
+## Part A -- Windows App SDK APIs
+
+**Full API reference:** <https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/>
+
+> **Agent Rule:** Do not rely on a hardcoded namespace list -- the SDK is updated frequently. Instead, **search** the API reference above by converting the user's scenario into common programming keywords.
+
+### How to search
+
+1. **Translate** the user's request into API/programming terms. Examples:
+   - "I want to describe an image" -> search for: `image description`, `ImageDescription`, `describe image`
+   - "Add a notification" -> search for: `notification`, `toast`, `AppNotification`
+   - "Pick a file" -> search for: `file picker`, `StoragePicker`, `FileOpenPicker`
+   - "Make the window always on top" -> search for: `AppWindow`, `presenter`, `compact overlay`
+2. **Search** the [WinAppSDK API reference](https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/) using `web_search` or `web_fetch` with those keywords.
+3. **Verify** the class/method exists in the SDK version used by this project (check `.csproj` `<PackageReference>` for `Microsoft.WindowsAppSDK` version).
+
+### Key reference links
+
+| # | Link | When to consult |
+|---|---|---|
+| 1 | [WinAppSDK API Reference (full)](https://learn.microsoft.com/en-us/windows/windows-app-sdk/api/winrt/) | **Always** -- search and look up exact class/method signatures here |
+| 2 | [Windows App SDK overview](https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/) | Feature overview, architecture |
+| 3 | [Release notes (stable)](https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/stable-channel) | API availability, version support, breaking changes |
+| 4 | [Windows AI overview](https://learn.microsoft.com/en-us/windows/ai/) | All AI options: Windows AI APIs, Windows ML, Foundry Local |
+| 5 | [Get started with Windows AI APIs](https://learn.microsoft.com/en-us/windows/ai/apis/get-started) | Prerequisites, project setup, first AI call |
+| 6 | [Windows ML overview](https://learn.microsoft.com/en-us/windows/ai/new-windows-ml/overview) | Custom ONNX model inference |
+| 7 | [Foundry Local](https://learn.microsoft.com/en-us/windows/ai/foundry-local/get-started) | Run OSS LLMs locally |
+
+---
+
+## Part B -- Windows Platform SDK (UWP / WinRT APIs)
+
+**Full API reference:** <https://learn.microsoft.com/en-us/uwp/api/>
+
+> **Agent Rule:** The Platform SDK (`Windows.*` namespaces) is very large and constantly evolving. Do not rely on a hardcoded list. **Search** the API reference by translating the user's requirement into programming keywords.
+
+### How to search
+
+1. **Translate** the user's request into API/programming terms. Examples:
+   - "Send a Bluetooth message" -> search for: `Bluetooth`, `RFCOMM`, `BluetoothDevice`
+   - "Get the user's location" -> search for: `geolocation`, `Geolocator`, `position`
+   - "Read text from an image" -> search for: `OCR`, `text recognition`, `OcrEngine`
+   - "Copy to clipboard" -> search for: `clipboard`, `DataTransfer`, `DataPackage`
+2. **Search** the [Platform SDK API reference](https://learn.microsoft.com/en-us/uwp/api/) using `web_search` or `web_fetch` with those keywords.
+3. **Check for WinAppSDK equivalent** -- some Platform SDK APIs have newer equivalents in Part A. Always prefer the WinAppSDK version when both exist.
+
+### Key reference links
+
+| # | Link | When to consult |
+|---|---|---|
+| 1 | [Platform SDK API Reference (full)](https://learn.microsoft.com/en-us/uwp/api/) | **Search here** for any Windows capability not in WinAppSDK |
+| 2 | [Windows SDK downloads](https://developer.microsoft.com/windows/downloads/windows-sdk/) | SDK versions and downloads |
+
+---
+
+## Validation
+
+- Before implementing any platform feature, confirm the API is available in the current Windows App SDK version by checking the [release notes](https://learn.microsoft.com/en-us/windows/apps/windows-app-sdk/stable-channel).
+- For features requiring specific hardware (NPU), provide a graceful fallback for unsupported devices.
+- When both WinAppSDK and Platform SDK offer a similar API, prefer the WinAppSDK version.
+
+