feat: Copilot instructions for commit messages

Author: Zacgoose

.github/copilot-instructions.md

@@ -162,3 +162,44 @@ Detailed PowerShell coding conventions are in `.github/instructions/powershell-c
 - Do not create new Azure Function trigger folders — use the existing five triggers
 - Do not call `Write-Output` in HTTP functions — return an `[HttpResponseContext]` (the outer trigger handles `Push-OutputBinding`)
 - Do not hardcode tenant IDs or secrets — use environment variables and `Get-GraphToken`
+
+## Commit messages
+
+Generate all commit messages in **Conventional Commits** format:
+
+```
+<type>(<optional scope>): <description>
+
+[optional body]
+
+[optional footer(s)]
+```
+
+**Rules:**
+
+- **Type** is required and must be one of:
+  - `feat` — a new feature
+  - `fix` — a bug fix
+  - `docs` — documentation only
+  - `style` — formatting, whitespace, no code-behavior change
+  - `refactor` — code change that neither fixes a bug nor adds a feature
+  - `perf` — a performance improvement
+  - `test` — adding or correcting tests
+  - `build` — build system or dependency changes
+  - `ci` — CI/CD configuration changes
+  - `chore` — routine maintenance, no production code change
+  - `revert` — reverts a previous commit
+- **Scope** is optional and given in parentheses after the type (e.g. `feat(identity):`). Use a short, lowercase area name when it adds clarity.
+- **Description** is a short, imperative-mood summary ("add", not "added"/"adds"), lowercase, no trailing period, ideally ≤ 72 characters.
+- **Body** (optional) explains the *what* and *why*, not the *how*. Separate it from the description with one blank line.
+- **Breaking changes** are indicated with a `!` before the colon (e.g. `feat!:`) and/or a `BREAKING CHANGE:` footer describing the change.
+- Reference issues/PRs in the footer where relevant (e.g. `Closes #123`).
+
+**Examples:**
+
+```
+feat(identity): add bulk user offboarding endpoint
+fix(graph): handle expired token on retry
+docs: update authentication model overview
+refactor(standards)!: rename remediation parameter
+```