design-explore/image-maker: use free Ming Image 0.1 Design via /api/v1/images

- Ming (inclusionai/ming-image-0.1-design) is free and built for graphic-design
  output with legible in-image text; now the preferred mockup model.
- Ming is a true image-generation model: the chat/completions endpoint rejects
  it (HTTP 404). Documented the /api/v1/images call + base64 decode recipe.
- Kept paid chat-image models as a documented fallback.
- Fixed the API key location: OPENROUTER_API_KEY is in /home/sam/.secrets,
  NOT ~/.config/environment.d/10-secrets.conf as the old text claimed.

agents/image-maker.md

@@ -1,6 +1,6 @@
 ---
 provider: omniroute
-description: Image generation via OpenRouter chat completions API
+description: Image generation via OpenRouter images + chat completions APIs
 model: openrouter/openai/gpt-5-image-mini
 memory: project
 thinking: off
@@ -18,10 +18,42 @@ You are an image generation specialist. You have ONE job: call the remote API an
 - If no API key is available, say: "No OPENROUTER_API_KEY found." Then STOP.
 
 ## Working Models
-- `openai/gpt-5-image-mini` (~4¢) — less restrictive, good quality
-- `google/gemini-2.5-flash-image` (~4¢) — Google content filters apply
 
-## API Call Format
+**Prefer `inclusionai/ming-image-0.1-design` — it is FREE.**
+
+| Model | Endpoint | Cost | Notes |
+|---|---|---|---|
+| `inclusionai/ming-image-0.1-design` | `/api/v1/images` | **free** | inclusionAI text-to-image for graphic design; excellent legible text rendering inside the image. Best default for UI mockups. |
+| `openai/gpt-5-image-mini` | `/api/v1/chat/completions` | ~4¢ | less restrictive, good quality |
+| `google/gemini-2.5-flash-image` | `/api/v1/chat/completions` | ~4¢ | Google content filters apply |
+
+⚠️ Endpoint matters. Most image models are chat models that return `choices[0].message.images[0].image_url.url`. **Ming is not** — it is a true image-generation model and the chat endpoint rejects it with HTTP 404 (`"... is an image generation model and cannot be used with the chat/completions endpoint"`). Ming must use `/api/v1/images`.
+
+## API Call Format — Ming (preferred, free)
+
+```bash
+curl -s https://openrouter.ai/api/v1/images \
+  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "model": "inclusionai/ming-image-0.1-design",
+    "prompt": "<detailed description>"
+  }' -o /tmp/ming.json
+```
+
+Returns `data[0].b64_json` (base64 PNG) and `data[0].media_type`. Decode to a file:
+
+```bash
+python3 -c "
+import json,base64
+r=json.load(open('/tmp/ming.json'))['data'][0]
+open('/tmp/design-explore-1.png','wb').write(base64.b64decode(r['b64_json']))
+print('saved /tmp/design-explore-1.png')
+"
+```
+
+## API Call Format — paid chat-image models (fallback)
+
 ```bash
 curl -s https://openrouter.ai/api/v1/chat/completions \
   -H "Authorization: Bearer $OPENROUTER_API_KEY" \
@@ -35,6 +67,14 @@ curl -s https://openrouter.ai/api/v1/chat/completions \
 The image comes back as base64 in `choices[0].message.images[0].image_url.url`. Save it to a file with proper extension.
 
 ## API Key
-Get OPENROUTER_API_KEY from `~/.config/environment.d/10-secrets.conf` (source it first).
+
+`OPENROUTER_API_KEY` lives in **`/home/sam/.secrets`** (a plain `KEY=value` file). Load it with:
+
+```bash
+set -a; . /home/sam/.secrets; set +a
+echo "${OPENROUTER_API_KEY:+key loaded}"
+```
+
+It is NOT in `~/.config/environment.d/10-secrets.conf` — older versions of this file claimed that and the call failed.
 
 Write detailed, specific prompts. Save images to the user's current working directory or a specified path. Tell the user where you saved the file.

skills/design-explore/SKILL.md

@@ -7,6 +7,8 @@ description: Generate visual UI design mockups as images for exploration and ide
 
 Generate visual UI mockups. Asks the user what to design, pulls design tokens or style references, and calls `image-maker` to produce high-fidelity mockup images.
 
+> **Image model:** use `inclusionai/ming-image-0.1-design` — it is **free**, and it is specifically built for graphic-design output with legible text rendering inside the image, which is exactly what UI mockups need. It is a true image-generation model and must be called on OpenRouter's `/api/v1/images` endpoint (NOT `/chat/completions`). See the `image-maker` subagent for the exact call.
+
 ---
 
 ## 🎨 Visual System & Image Prompting Rules
@@ -32,11 +34,13 @@ curl -sL <DESIGN_MD_URL> -o /tmp/design-tokens.md
 
 ### Step 3: Call `image-maker`
 
+Instruct it to use the free Ming model via the images endpoint.
+
 ```bash
 Agent(
   subagent_type: "image-maker",
   description: "Generate design mockup images",
-  prompt: "High-fidelity UI mockup for {what}. Aesthetic: {vibe/tokens}. Clean browser frame, non-generic layout, bold typography, rich contrast, professional SaaS/web app finish.",
+  prompt: "Use model inclusionai/ming-image-0.1-design via POST https://openrouter.ai/api/v1/images (free). Generate a high-fidelity UI mockup for {what}. Aesthetic: {vibe/tokens}. Clean browser frame, non-generic layout, bold typography, rich contrast, professional SaaS/web app finish. Save as /tmp/design-explore-<N>.png and report the path.",
   max_turns: 3
 )
 ```