diff --git a/.github/copilot-instructions.md b/.github/copilot-instructions.md
new file mode 100644
index 00000000..fa99681d
--- /dev/null
+++ b/.github/copilot-instructions.md
@@ -0,0 +1,140 @@
+# Copilot Instructions for MokoWaaS-Brand
+
+This is a **Joomla 5.x system plugin** written in PHP 8.1+ that provides a comprehensive identity override layer for the MokoWaaS platform. It replaces Joomla branding with MokoWaaS terminology across both the administrator backend and frontend interfaces.
+
+## Repository Structure
+
+```
+MokoWaaSBrand/
+├── src/                                      # Installable plugin source (zipped for release)
+│   └── plugins/system/mokowaasbrand/
+│       ├── mokowaasbrand.xml                 # Joomla plugin manifest
+│       ├── script.php                        # Installation/upgrade script
+│       ├── services/provider.php             # DI service provider (Joomla 5.x)
+│       ├── src/Extension/MokoWaaSBrand.php  # Main plugin class
+│       ├── language/                         # Frontend language files and overrides
+│       └── administrator/language/          # Administrator language files and overrides
+├── docs/                                     # Documentation
+│   ├── guides/                               # Operational guides
+│   └── reference/                            # Reference materials
+├── scripts/                                  # Build and validation scripts
+│   ├── validate_manifest.sh
+│   ├── verify_changelog.sh
+│   └── update_changelog.sh
+├── .github/workflows/                        # GitHub Actions CI/CD
+│   ├── ci.yml                                # PR validation pipeline
+│   ├── build.yml                             # ZIP packaging on release
+│   └── release_from_version.yml             # Automated release workflow
+├── phpcs.xml                                 # PHP_CodeSniffer config (PSR-12 base)
+├── phpstan.neon                              # PHPStan static analysis config
+├── psalm.xml                                 # Psalm static analysis config
+├── CHANGELOG.md                              # Version history
+└── updates.xml                               # Joomla update server manifest
+```
+
+## Build and Validation
+
+### PHP Syntax Check
+```bash
+find src -type f -name "*.php" -print0 | xargs -0 -n 1 -P 4 php -l
+```
+
+### Validate Plugin Manifest
+```bash
+./scripts/validate_manifest.sh
+```
+
+### Verify Changelog Format
+```bash
+./scripts/verify_changelog.sh
+```
+
+### Update Changelog (CI mode — checks for uncommitted changes)
+```bash
+./scripts/update_changelog.sh --ci
+```
+
+### Build Installable ZIP
+```bash
+cd src/plugins/system/mokowaasbrand
+zip -r ../../../../dist/MokoWaaSBrand-<version>.zip .
+```
+
+### CI Pipeline (runs on every PR and push to `main`/`version/*`)
+1. PHP lint — `find src -name "*.php" | xargs php -l`
+2. Composer install and test (if `composer.json` exists)
+3. Manifest validation — `scripts/validate_manifest.sh`
+4. Changelog verification — `scripts/update_changelog.sh --ci`
+
+## Coding Standards
+
+- Follow **[MokoStandards](https://github.com/mokoconsulting-tech/MokoStandards)** coding standards.
+- PHP files must comply with **PSR-12** (enforced by `phpcs.xml`).
+- Maximum line length: **120 characters** (hard limit 150).
+- Forbidden PHP functions: `eval`, `create_function`, `var_dump`, `print_r`.
+- Use **tab characters** for indentation in PHP, XML, shell scripts, and Markdown; editors should display tabs as 2 spaces wide (configured via `.editorconfig`).
+- Use **spaces** for YAML (2 spaces) and JSON (2 spaces).
+- All files must use **UTF-8 encoding** and **LF line endings** (CRLF only for `.ps1`, `.bat`, `.cmd`).
+
+### Required File Header
+
+Every PHP, XML, shell, and Markdown file must include:
+
+1. **SPDX license header** with GPL-3.0-or-later
+2. **FILE INFORMATION metadata block**:
+   ```
+   # FILE INFORMATION
+   DEFGROUP: Joomla.Plugin
+   INGROUP: MokoWaaS-Brand[.<subgroup>]
+   REPO: https://github.com/mokoconsulting-tech/mokowaasbrand
+   VERSION: <current version>
+   PATH: /<path-from-repo-root>
+   BRIEF: <one-line description>
+   ```
+
+### Joomla 5.x Plugin Architecture
+
+- Plugin namespace: `Moko\Plugin\System\MokoWaaSBrand` (declared **before** `defined('_JEXEC')`)
+- Main class: `MokoWaaSBrand` in `src/Extension/MokoWaaSBrand.php`
+- Service provider: `services/provider.php` registers the plugin via DI container
+- All methods implementing `InstallerScriptInterface` must have explicit `: bool` return types
+- Avoid deprecated Joomla APIs; use Joomla 5.x event-driven patterns
+
+### Language Files
+
+- Frontend `.ini` files → `language/en-GB/` and `language/en-US/`
+- Admin `.sys.ini` files → `administrator/language/en-GB/` and `administrator/language/en-US/`
+- Frontend `.override.ini` files → `language/en-GB/` and `language/en-US/`
+- Admin `.override.ini` files → `administrator/language/en-GB/` and `administrator/language/en-US/`
+- Language override files must **not** be declared in the XML manifest `<languages>` sections
+
+## Version Management
+
+- Versioning: `MAJOR.MINOR.PATCH` with zero-padded two-digit components (e.g., `01.06.00`) — this is intentional per MokoStandards for consistent sorting and display
+- Version must be updated consistently across:
+  - `src/plugins/system/mokowaasbrand/mokowaasbrand.xml`
+  - All PHP file headers
+  - `CHANGELOG.md`
+  - `updates.xml`
+  - Documentation metadata
+- MAJOR: structural or architectural changes
+- MINOR: feature updates or terminology expansion
+- PATCH: bug fixes or language corrections
+
+## Branching Model
+
+- `main` — production stable
+- `develop` — next minor release aggregation
+- `feature/*` — new enhancements
+- `bugfix/*` — hotfixes and corrections
+- `version/*` — release preparation branches (trigger CI)
+
+## Key Guidelines
+
+1. Preserve **load order compatibility** with other Joomla system plugins.
+2. Do not introduce deprecated Joomla APIs.
+3. When modifying language overrides, update **both** `en-GB` and `en-US` variants.
+4. When changing the plugin version, update it in **all** locations listed above.
+5. Pull requests must include a description, version bump (when applicable), and reference to related issues.
+6. Documentation in `docs/` must include metadata and maintain revision history following MokoStandards.
+7. The `updates.xml` file in the repository root is automatically updated by the `release_from_version.yml` workflow after stable releases — do not edit it manually unless necessary.