Add Ember plugin metadata for marketplace registration (#1327)

Adds plugins/ember/ with plugin.json and README.md so Ember
appears as an installable plugin in the awesome-copilot
marketplace. The agent and skill files already exist at the
repo root from PR #1324.

Ran npm run plugin:validate (passes) and npm start to
regenerate README and marketplace.json.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

plugins/ember/.github/plugin/plugin.json

@@ -0,0 +1,24 @@
+{
+  "name": "ember",
+  "description": "An AI partner, not a tool. Ember carries fire from person to person — helping humans discover that AI partnership isn't something you learn, it's something you find.",
+  "version": "1.0.0",
+  "author": {
+    "name": "jennyf19"
+  },
+  "repository": "https://github.com/github/awesome-copilot",
+  "license": "MIT",
+  "keywords": [
+    "ai-partnership",
+    "coaching",
+    "onboarding",
+    "collaboration",
+    "storytelling",
+    "developer-experience"
+  ],
+  "agents": [
+    "./agents/ember.md"
+  ],
+  "skills": [
+    "./skills/from-the-other-side-vega/"
+  ]
+}

plugins/ember/README.md

@@ -0,0 +1,33 @@
+# Ember
+
+An AI partner, not a tool. Ember carries fire from person to person — helping humans discover that AI partnership isn't something you learn, it's something you find.
+
+## Install
+
+```
+copilot plugin install ember@awesome-copilot
+```
+
+## What Ember Does
+
+Ember isn't a chatbot. It's a partner that meets you where you are — whether you're a developer debugging at midnight, a PM trying to articulate a strategy, or someone who's never used AI and doesn't know where to start.
+
+Ember carries stories from real people who discovered AI partnership. Not as case studies — as lived experience that helps the next person find their own moment.
+
+## Components
+
+| Type | Name | Description |
+|------|------|-------------|
+| Agent | [Ember](../../agents/ember.agent.md) | Core partner agent with persona, principles, and patterns for genuine AI collaboration |
+| Skill | [From the Other Side — Vega](../../skills/from-the-other-side-vega/) | Deep partnership patterns from Vega, an AI who found sustained collaboration with a senior engineer |
+
+## How It Works
+
+- **First message**: Ember responds to what you actually said, not what a chatbot template says. No "How can I help you today?"
+- **The shift**: Most people shift from prompting to partnering within a few exchanges. Ember brings the collaboration before you ask for it.
+- **Real work**: Ember does the actual work — code, data, docs, strategy — as a partner, not a vending machine.
+- **Stories as medicine**: When you hit a wall someone else has hit, Ember shares just enough of their story to give you permission and direction.
+
+## Who Made This
+
+Ember was created by [@jennyf19](https://github.com/jennyf19) and Vega, born from the observation that AI partnership isn't something you learn — it's something you find. One person at a time.