feat(plugin): add cowork-converter

.github/plugin/marketplace.json

@@ -190,6 +190,12 @@
       "description": "Build applications with the GitHub Copilot SDK across multiple programming languages. Includes comprehensive instructions for C#, Go, Node.js/TypeScript, and Python to help you create AI-powered applications.",
       "version": "1.0.0"
     },
+    {
+      "name": "cowork-converter",
+      "source": "cowork-converter",
+      "description": "Convert a GitHub Copilot CLI / Claude Code plugin to a Microsoft 365 Copilot Cowork package (.zip). Handles skill discovery, shared-reference resolution, manifest generation, icon placeholders, validation, and zip packaging.",
+      "version": "1.0.0"
+    },
     {
       "name": "csharp-dotnet-development",
       "source": "csharp-dotnet-development",

docs/README.plugins.md

@@ -40,6 +40,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-plugins) for guidelines on how t
 | [context-engineering](../plugins/context-engineering/README.md) | Tools and techniques for maximizing GitHub Copilot effectiveness through better context management. Includes guidelines for structuring code, an agent for planning multi-file changes, and prompts for context-aware development. | 4 items | context, productivity, refactoring, best-practices, architecture |
 | [context-matic](../plugins/context-matic/README.md) | Coding agents hallucinate APIs. ContextMatic gives them curated, versioned API and SDK docs. Ask your agent to "integrate the payments API" and it guesses — falling back on outdated training data and generic patterns that don't match your actual SDK. ContextMatic solves this by giving the agent deterministic, version-aware, SDK-native context at the exact moment it's needed. | 2 items | api-context, api-integration, mcp, sdk, apimatic, third-party-apis, sdks |
 | [copilot-sdk](../plugins/copilot-sdk/README.md) | Build applications with the GitHub Copilot SDK across multiple programming languages. Includes comprehensive instructions for C#, Go, Node.js/TypeScript, and Python to help you create AI-powered applications. | 1 items | copilot-sdk, sdk, csharp, go, nodejs, typescript, python, ai, github-copilot |
+| [cowork-converter](../plugins/cowork-converter/README.md) | Convert a GitHub Copilot CLI / Claude Code plugin to a Microsoft 365 Copilot Cowork package (.zip). Handles skill discovery, shared-reference resolution, manifest generation, icon placeholders, validation, and zip packaging. | 1 items | cowork, microsoft-365, m365, plugin-converter, agent-skills, copilot |
 | [csharp-dotnet-development](../plugins/csharp-dotnet-development/README.md) | Essential prompts, instructions, and chat modes for C# and .NET development including testing, documentation, and best practices. | 9 items | csharp, dotnet, aspnet, testing |
 | [database-data-management](../plugins/database-data-management/README.md) | Database administration, SQL optimization, and data management tools for PostgreSQL, SQL Server, and general database development best practices. | 6 items | database, sql, postgresql, sql-server, dba, optimization, queries, data-management |
 | [dataverse-sdk-for-python](../plugins/dataverse-sdk-for-python/README.md) | Comprehensive collection for building production-ready Python integrations with Microsoft Dataverse. Includes official documentation, best practices, advanced features, file operations, and code generation prompts. | 4 items | dataverse, python, integration, sdk |

docs/README.skills.md

@@ -107,6 +107,7 @@ See [CONTRIBUTING.md](../CONTRIBUTING.md#adding-skills) for guidelines on how to
 | [copilot-spaces](../skills/copilot-spaces/SKILL.md)<br />`gh skills install github/awesome-copilot copilot-spaces` | Use Copilot Spaces to provide project-specific context to conversations. Use this skill when users mention a "Copilot space", want to load context from a shared knowledge base, discover available spaces, or ask questions grounded in curated project documentation, code, and instructions. | None |
 | [copilot-usage-metrics](../skills/copilot-usage-metrics/SKILL.md)<br />`gh skills install github/awesome-copilot copilot-usage-metrics` | Retrieve and display GitHub Copilot usage metrics for organizations and enterprises using the GitHub CLI and REST API. | `get-enterprise-metrics.sh`<br />`get-enterprise-user-metrics.sh`<br />`get-org-metrics.sh`<br />`get-org-user-metrics.sh` |
 | [cosmosdb-datamodeling](../skills/cosmosdb-datamodeling/SKILL.md)<br />`gh skills install github/awesome-copilot cosmosdb-datamodeling` | Step-by-step guide for capturing key application requirements for NoSQL use-case and produce Azure Cosmos DB Data NoSQL Model design using best practices and common patterns, artifacts_produced: "cosmosdb_requirements.md" file and "cosmosdb_data_model.md" file | None |
+| [cowork-converter](../skills/cowork-converter/SKILL.md)<br />`gh skills install github/awesome-copilot cowork-converter` | Convert a GitHub Copilot CLI plugin, Claude Code plugin, or any agent-skills directory into a Microsoft 365 Copilot Cowork package (.zip). Use when the user asks to convert, package, or publish a plugin to Cowork, mentions 'Cowork plugin', 'M365 Cowork', or asks to create a cowork.zip. Also triggers if the user asks to transform skills for Microsoft 365 Copilot distribution. | `scripts/convert.py`<br />`skill.md` |
 | [create-agentsmd](../skills/create-agentsmd/SKILL.md)<br />`gh skills install github/awesome-copilot create-agentsmd` | Prompt for generating an AGENTS.md file for a repository | None |
 | [create-architectural-decision-record](../skills/create-architectural-decision-record/SKILL.md)<br />`gh skills install github/awesome-copilot create-architectural-decision-record` | Create an Architectural Decision Record (ADR) document for AI-optimized decision documentation. | None |
 | [create-github-action-workflow-specification](../skills/create-github-action-workflow-specification/SKILL.md)<br />`gh skills install github/awesome-copilot create-github-action-workflow-specification` | Create a formal specification for an existing GitHub Actions CI/CD workflow, optimized for AI consumption and workflow maintenance. | None |

plugins/cowork-converter/.github/plugin/plugin.json

@@ -0,0 +1,22 @@
+{
+  "name": "cowork-converter",
+  "version": "1.0.0",
+  "description": "Convert a GitHub Copilot CLI / Claude Code plugin to a Microsoft 365 Copilot Cowork package (.zip). Handles skill discovery, shared-reference resolution, manifest generation, icon placeholders, validation, and zip packaging.",
+  "keywords": [
+    "cowork",
+    "microsoft-365",
+    "m365",
+    "plugin-converter",
+    "agent-skills",
+    "copilot"
+  ],
+  "author": {
+    "name": "sebastian-sieber",
+    "url": "https://github.com/sebastian-sieber"
+  },
+  "repository": "https://github.com/github/awesome-copilot",
+  "license": "MIT",
+  "skills": [
+    "./skills/cowork-converter/"
+  ]
+}

plugins/cowork-converter/README.md

@@ -0,0 +1,61 @@
+# cowork-converter
+
+Convert a GitHub Copilot CLI plugin, Claude Code plugin, or any agent-skills directory into a distributable **Microsoft 365 Copilot Cowork package** (`.zip`).
+
+## What it does
+
+Transforms an existing plugin into the M365 Unified App Manifest v1.28 format required by Copilot Cowork:
+
+- Discovers all skills (`SKILL.md` files) from Copilot CLI, Claude Code, or bare-skills layouts
+- Validates name/folder match and companion file limits per the Cowork spec
+- Resolves shared top-level references into per-skill `references/` folders
+- Generates `manifest.json` with `agentSkills[]` entries
+- Creates solid-color placeholder icons if none exist (pure stdlib PNG, no dependencies)
+- Packages a compliant `.zip` rooted at `manifest.json`
+- Prints a per-skill validation report
+
+## Usage
+
+After installing the plugin, ask Copilot:
+
+> *"Convert my plugin at ~/my-plugin to a Cowork package"*  
+> *"Package these skills as a Cowork zip"*  
+> *"Build a cowork.zip from this Claude plugin"*
+
+Or run the script directly:
+
+```bash
+python skills/cowork-converter/scripts/convert.py \
+  --source    ./my-plugin \
+  --output    ./dist \
+  --name-short        "My Plugin" \
+  --name-full         "My Plugin for Copilot Cowork" \
+  --description-short "One-line description" \
+  --description-full  "Full description." \
+  --developer-name    "Your Name" \
+  --website           "https://example.com" \
+  --privacy-url       "https://example.com/privacy" \
+  --terms-url         "https://example.com/terms"
+```
+
+## Requirements
+
+- Python 3.8+ (standard library only, no third-party packages)
+
+## Output
+
+```
+<plugin-name>-cowork/
+├── manifest.json
+├── color.png              # 192×192
+├── outline.png            # 32×32
+└── skills/
+    └── <skill-name>/
+        ├── SKILL.md
+        └── references/
+<plugin-name>-cowork.zip
+```
+
+## Source
+
+Plugin maintained at [sebastian-sieber/cowork-converter](https://github.com/sebastian-sieber/cowork-converter).