Add agentic labeler workflow for issues and PRs

.github/skills/agentic-labeler/SKILL.md

@@ -0,0 +1,82 @@
+---
+name: agentic-labeler
+description: >-
+  Labels issues and pull requests in the dotnet/maui repository based on
+  technical content, area-matching rules, and platform-file conventions.
+  Used by the gh-aw agentic-labeler workflow and available for batch
+  evaluation and interactive Copilot CLI usage.
+metadata:
+  author: dotnet-maui
+  version: "1.0"
+---
+
+# Agentic Labeler
+
+Labeling rules for the [dotnet/maui](https://github.com/dotnet/maui) repository. These rules are the canonical source of truth for how issues and PRs should be labeled. They are consumed by the `agentic-labeler` gh-aw workflow and can also be used standalone for batch evaluation or interactive labeling.
+
+## Label discovery
+
+- Fetch the current list of labels using the `list_label` MCP tool (provided by the `labels` toolset). Note the **singular** name — it is `list_label`, not `list_labels`.
+- **Important pagination caveat:** the `list_label` tool only returns the first ~100 labels (no pagination). This repo has ~440 labels, so many `area-*`, `platform/*`, and status labels will be missing from the listing. If you have a strong candidate label name in mind that isn't in the listing, **verify it exists** with the `get_label` tool before adding it. The label families enumerated below (`area-*`, `platform/*`, `t/*`, `s/*`, `i/*`, `p/*`) are reliable guides; use `get_label` for anything else.
+- You may apply **any** existing label, not just `area-*` and `platform/*`. Examples of other useful label families that exist in this repo (with **exact** names — emoji suffixes are part of the label and must be matched verbatim):
+  - **Kind:** `t/bug`, `t/enhancement ☀️`, `t/docs 📝`, `t/breaking 💥`, `t/native-embedding`, `t/desktop`, `t/a11y`
+  - **Status / signal (issues):** `i/regression`, `s/needs-repro`, `s/needs-info`, `s/needs-attention`, `s/duplicate 2️⃣`, `s/no-repro`, `s/not-a-bug`
+  - **Priority:** `p/0`, `p/1`, `p/2`, `p/3`
+- **PR-specific status caveat:** **do not** apply `s/needs-info` or `s/needs-repro` to pull requests — repo automation rewrites or removes them and posts a comment. On PRs, use `s/pr-needs-author-input` instead when more information is needed.
+- Do **not** create new labels. Only labels that already exist in the repository will be accepted.
+
+## Labeling rules
+
+### `area-*` labels (issues and PRs)
+
+Pick one or more `area-*` labels based on the subject matter:
+
+- Specific control mentioned → matching `area-controls-<name>` (e.g., `CollectionView` → `area-controls-collectionview`, `Entry` → `area-controls-entry`).
+- Layout, measure/arrange, sizing issues → `area-layout`.
+- Navigation, Shell routing, page navigation → `area-navigation` (or `area-controls-shell` when Shell-specific).
+- XAML parsing, markup extensions, XamlC, source generators → `area-xaml`.
+- Hot reload, build, MSBuild, workload, project templates, tooling → `area-tooling`, `area-templates`, or `area-setup` as appropriate.
+- BlazorWebView / Blazor hybrid → `area-blazor`.
+- Essentials APIs (non-UI: connectivity, sensors, preferences, etc.) → `area-essentials`.
+- Drawing / Microsoft.Maui.Graphics → `area-drawing`.
+- Gestures (tap, pan, swipe, pinch) → `area-gestures`.
+- Lifecycle, hosting, app startup, DI → `area-core-lifecycle` / `area-core-hosting`.
+- Dispatcher / main thread / threading → `area-core-dispatching`.
+- Localization / RTL / culture → `area-localization`.
+- Docs only → `area-docs`.
+
+Prefer the most specific label. It is fine to apply both a generic and a specific area label (e.g., `area-layout` + `area-controls-collectionview`) when both clearly apply.
+
+### `platform/*` labels
+
+This is the most important behavior for PRs.
+
+**For pull requests**, infer `platform/*` labels primarily from the **changed files**, using the rules below. Each rule maps a file pattern to one or more platform labels. Apply a `platform/*` label if **any** changed file matches that pattern. The path patterns intentionally target the established MAUI source-layout conventions (`Platform/<Name>/` and `Platforms/<Name>/`) — do not match on bare `/Android/`, `/iOS/`, `/Windows/`, etc., as those occur in templates, docs, and unrelated tooling paths.
+
+Note on iOS / MacCatalyst: file-extension patterns and directory patterns map differently because of MAUI's compilation conventions — they are split into separate rows below.
+
+| File pattern (changed in the PR) | Label(s) to apply |
+| --- | --- |
+| `*.android.cs`, `*.Android.cs`, paths containing `/Platform/Android/`, `/Platforms/Android/`, `/AndroidNative/` | `platform/android` |
+| `*.ios.cs`, `*.iOS.cs` (file-extension pattern — these compile for **both** iOS and MacCatalyst) | `platform/ios` **and** `platform/macos` |
+| Paths containing `/Platform/iOS/` or `/Platforms/iOS/` (directory pattern — these compile **only** for the iOS TFM) | `platform/ios` only |
+| `*.maccatalyst.cs`, `*.MacCatalyst.cs`, paths containing `/Platform/MacCatalyst/`, `/Platforms/MacCatalyst/` | `platform/macos` |
+| `*.windows.cs`, `*.Windows.cs`, paths containing `/Platform/Windows/`, `/Platforms/Windows/` | `platform/windows` |
+| `*.tizen.cs`, paths containing `/Platform/Tizen/`, `/Platforms/Tizen/` | `platform/tizen` |
+
+Notes:
+
+- If a PR touches **only shared / cross-platform code** (e.g., `src/Core/src/*.cs` without a platform suffix, or `src/Controls/src/Core/`), do **not** apply any `platform/*` label.
+- If a PR touches **multiple platforms**, apply each matching `platform/*` label.
+- `.ios.cs` files compile for both iOS and MacCatalyst (see split table rows above).
+- `.maccatalyst.cs` files do **not** compile for iOS — apply only `platform/macos` for those.
+
+**For issues**, infer `platform/*` labels only if the reporter clearly indicates a platform (explicit mention of Android / iOS / macOS / Windows / Tizen in the title, body, or attached logs/stack traces). Do not guess. If the report says "all platforms" or doesn't specify, apply no `platform/*` label.
+
+### What NOT to do
+
+- Do **not** create new labels — apply only labels that already exist in the repository.
+- Do **not** add `platform/*` labels to PRs that don't touch platform-specific files.
+- Do **not** post a comment summarizing the labels — labels speak for themselves.
+- Do **not** close, lock, or otherwise modify the issue/PR beyond labeling.
+- Be conservative; precision beats recall. Only apply labels that clearly fit.