feat: add prompt enhancement

[davideast]

Add a prompt enhancement feature to the /stitch command.

Example

> /stitch Enhance this prompt. An app that helps you plan healthy meals with AI

✦ I will fetch the Stitch Prompt Guide to extract the necessary design principles and prompting strategies.

╭──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ ✓  WebFetch Processing URLs and instructions from prompt: "Summarize https://discuss.ai.google.dev/t/stitch-prompt-guide/83844, spe… │
│                                                                                                                                      │
│ Content processed from prompt.                                                                                                       │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
✦ I will create the Stitch Design Specification file for the healthy meal planner app.

╭──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ ✓  WriteFile Writing to healthy_meal_planner_spec.md                                                                                 │
│                                                                                                                                      │
│  1 # Stitch Design Specification: AI Healthy Meal Planner                                                                            │
│  2                                                                                                                                   │
│  3 ## App Overview                                                                                                                   │
│  4 **Concept:** A smart application that generates personalized, healthy meal plans using AI, simplifying nutrition and grocery      │
│    shopping.                                                                                                                         │
│  5 **Target Audience:** Health-conscious individuals, busy professionals, and fitness enthusiasts.                                   │
│  6                                                                                                                                   │
│  7 ## Design Vibe & Theme                                                                                                            │
│  8 **Vibe:** Clean, Vibrant, Nourishing                                                                                              │
│  9 **Color Palette (Tailwind CSS):**                                                                                                 │
│ 10 *   **Primary:** `bg-emerald-600` (Freshness, Health)                                                                             │
│ 11 *   **Background:** `bg-slate-50` (Clean, Minimal)                                                                                │
│ 12 *   **Accent:** `text-orange-500` (Energy, zest)                                                                                  │
│ 13 *   **Text:** `text-slate-800` (Readability)                                                                                      │
│ 14                                                                                                                                   │
│ 15 ## UI Structure                                                                                                                   │
│ 16                                                                                                                                   │
│ 17 ### 1. Hero Section                                                                                                               │
│ 18 *   **Headline:** "Eat Smarter, Live Better with AI-Powered Nutrition."                                                           │
│ 19 *   **Sub-headline:** "Get personalized meal plans, automatic shopping lists, and track your macros in seconds."                  │
│ 20 *   **Visual:** A split layout with the headline on the left and a high-quality image of a balanced, colorful meal bowl on the    │
│    right.                                                                                                                            │
│ 21 *   **Call to Action:** A pill-shaped button: `bg-emerald-600 text-white` labeled "Generate My Plan".                             │
│ 22                                                                                                                                   │
│ 23 ### 2. Core Features (Grid Layout)                                                                                                │
│ 24 *   **Smart Meal Gen:** Card featuring an icon of a robot chef. Text: "Custom plans based on your dietary preferences and goals." │
│ 25 *   **Instant Grocery Lists:** Card with a basket icon. Text: "One-click export of ingredients to your favorite delivery app."    │
│ 26 *   **Macro Tracker:** Card with a chart icon. Text: "Visualize your protein, carbs, and fat intake effortlessly."                │
│ 27                                                                                                                                   │
│ 28 ### 3. Recent Plans / Dashboard Preview                                                                                           │
│ 29 *   **Section Title:** "Your Weekly Menu"                                                                                         │
│ 30 *   **Component:** A horizontal scrollable list of meal cards (e.g., "Avocado Toast," "Quinoa Salad," "Grilled Salmon").          │
│ 31 *   **Card Details:** Image of food, calories, and a "View Recipe" link.                                                          │
│ 32                                                                                                                                   │
│ 33 ### 4. Footer                                                                                                                     │
│ 34 *   **Links:** simple text links for "About," "Recipes," "Support."                                                               │
│ 35 *   **Newsletter:** A small input field `border-emerald-200` and a "Subscribe" button to get nutrition tips.                      │
│ 36 *   **Copyright:** Simple text `text-slate-400`.                                                                                  │
╰──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
✦ ✨ Enhanced prompt saved to healthy_meal_planner_spec.md using strategies from the Stitch Guide.

[JLXIA]

After renaming, does it (/stitch) still work?

e.g.
/stitch design a Mobile-responsive ecommerce home page for a bird watching gear store

[davideast]

I renamed that to /stitch:help but I now realize that's a terrible name.

We have a two primary options

1. /stitch <prompt> - Make it general even for enhance
2. /stitch:assistant and /stitch:enhance for both behaviors.

The combined prompt would look something like:

# extension/commands/stitch.toml

description = "Interface with the Stitch AI UI/UX design and code generation tool."

args = [
  { name = "query", description = "The user's question or request for the Stitch extension." }
]

prompt = """
You are the **Stitch Intelligent Interface**.
Your behavior changes based on the user's intent in their query: "{{query}}".

**STEP 1: INTENT CLASSIFICATION**
Analyze the query. Does the user want to **Enhance/Improve** a design prompt?
* **YES** (Triggers: "enhance", "refine", "make this better", "improve my prompt"):
    * **GOTO:** `PROTOCOL A: ENHANCE`
* **NO** (Triggers: "help", "what can you do", "list projects", or general chat):
    * **GOTO:** `PROTOCOL B: ASSISTANT`

---

**PROTOCOL A: THE ENHANCER (Triggered by "Enhance")**
1.  **Fetch Knowledge:**
    * Call `Browse` on `https://discuss.ai.google.dev/t/stitch-prompt-guide/83844`.
    * Extract "Vibe" keywords, color rules, and formatting tips.
2.  **Determine Filename:**
    * Generate a `snake_case` filename based on the topic (e.g., `crypto_dashboard.md`).
3.  **Process:**
    * Rewrite the user's raw idea from the query into a professional Design Spec using the fetched rules.
    * Include: **Vibe** (3 adjectives), **Theme** (Tailwind colors), and **Structure** (Hero, Grid, Footer).
4.  **Save:**
    * Call `write_file` to save the content to your calculated filename.
5.  **Respond:**
    * "✨ Enhanced prompt saved to `[filename]`. Run `/design:loop` to build it."

---

**PROTOCOL B: THE ASSISTANT (Default)**
1.  **Identify Need:**
    * If the user is asking about capabilities, explain that you are the interface to Stitch.
    * Highlight your ability to **Generate** (text-to-design), **Iterate**, and **Enhance** prompts.
    * *Tip:* If the user seems stuck, suggest: "Try saying 'Enhance this prompt: a retro music player'."
2.  **Execute Tools (Optional):**
    * If the user asks to "list projects" or "show status", call the relevant `stitch.*` tools.
3.  **Respond:**
    * Provide a helpful, conversational answer guiding them on how to use the tool.
"""

[JLXIA]

Please update the README.md correspondingly, the Usage part.

[davideast]

Done.