feat: add example gallery with auto-generated screenshots (#253)

* feat: add script to generate 300x300 grid-cell.png screenshots for examples

- Add generate-grid-screenshots.spec.ts Playwright test to capture screenshots
- Add npm run generate:screenshots command (Docker-based for Santa compatibility)
- Add sharp dependency for image resizing with centered-fill mode
- Generate grid-cell.png for 14 example servers (only React for basic-server-* series)

The screenshots are 300x300 PNG images cropped with centered fill mode,
suitable for use in a grid layout showcasing the examples.

* docs: add example gallery grid to README

Add a 3-column visual grid showcasing 14 example MCP Apps with:
- Thumbnail screenshots (300x300 grid-cell.png)
- Clickable links to example directories
- Hover tooltips with brief descriptions

Organized by visual impact: 3D/WebGL examples first, then
visualizations, charts, monitoring, and starter templates.

* fix: use aspect-fit instead of crop for screenshots

Change from fit: 'cover' (crops) to fit: 'contain' (letterbox)
so the full app content is visible without cropping.

* feat: improve screenshot generation

- Constrain viewport to 500px width for consistent rendering
- Wait 5 seconds for full app load (tiles, animations, data)
- Screenshot just the inner iframe (no extra whitespace)
- Save both screenshot.png (full-size) and grid-cell.png (300x300 thumbnail)
- Use contain mode to preserve aspect ratio

* fix: use cover mode with top alignment for grid thumbnails

No letterboxing - crops to fill 300x300, aligned to top so headers
and important content are always visible.

* feat: improve screenshot gallery

- Remove integration-server from gallery (it's for E2E testing only)
- Add 30s extra wait for Map and Video servers to load fully
- Improve Three.js default scene: isometric rotation + better lighting
- Update README: Starter Templates row with links to all framework variants
  (React, Vue, Svelte, Preact, Solid, Vanilla JS)
- Regenerate all screenshots with updated settings

* fix: improve README gallery layout

- Fix uneven column widths by using minimal separator
- Move Starter Templates to separate 2-cell table with description
- Add screenshot.png to top of each example README (13 examples)
- Shorten tooltips for cleaner table

* revert to document.write again; cesiumjs doesn't like srcdoc, period.

* fix: map-server screenshot now renders properly

- Merged ochafik/post-fixes which reverts sandbox from srcdoc to document.write
  (CesiumJS doesn't work with srcdoc iframes)
- Fixed map-server name in screenshot test ('Map Server' not 'CesiumJS Map Server')
- Simplified screenshot generation script (removed complex debugging code)
- Increased map-server wait time to 45s for reliable tile loading
- Regenerated all 13 screenshots

* fix: remove redundant screenshots from READMEs

Remove the simple \![Screenshot](screenshot.png) line from READMEs that
already had nicer HTML table screenshots. Keep it only for examples
that didn't have existing screenshots.

* docs: move gallery to Examples section

- Move screenshot gallery from top of README to Examples section
- Remove redundant list of basic examples (now shown visually in gallery)
- Clean up duplicate run instructions

* fix: remove empty header row from starter templates table

* fix: remove empty header rows from both tables

* fix: add prettier-ignore to prevent table header expansion

* feat: use custom screenshot for video-resource-server

- Use better screenshot from PR #253 comment showing actual video playback
- Skip video-resource-server in screenshot generation script
- Add SKIP_SERVERS set for manually maintained screenshots

* fix: revert unrelated map-server name change

* fix: use correct server name 'CesiumJS Map Server' in screenshot test

Author: ochafik

README.md

@@ -56,19 +56,28 @@ Or edit your `package.json` manually:
 
 ## Examples
 
-Start with these foundational examples to learn the SDK:
-
-- [`examples/basic-server-vanillajs`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-vanillajs) — MCP server + MCP App using vanilla JS
-- [`examples/basic-server-react`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-react) — MCP server + MCP App using [React](https://github.com/facebook/react)
-- [`examples/basic-server-vue`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-vue) — MCP server + MCP App using [Vue](https://github.com/vuejs/vue)
-- [`examples/basic-server-svelte`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-svelte) — MCP server + MCP App using [Svelte](https://github.com/sveltejs/svelte)
-- [`examples/basic-server-preact`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-preact) — MCP server + MCP App using [Preact](https://github.com/preactjs/preact)
-- [`examples/basic-server-solid`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-server-solid) — MCP server + MCP App using [Solid](https://github.com/solidjs/solid)
-- [`examples/basic-host`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples/basic-host) — MCP host application supporting MCP Apps
+<!-- prettier-ignore-start -->
+| | | |
+|:---:|:---:|:---:|
+| [![Map](examples/map-server/grid-cell.png "Interactive 3D globe viewer using CesiumJS")](examples/map-server) | [![Three.js](examples/threejs-server/grid-cell.png "Interactive 3D scene renderer")](examples/threejs-server) | [![ShaderToy](examples/shadertoy-server/grid-cell.png "Real-time GLSL shader renderer")](examples/shadertoy-server) |
+| [**Map**](examples/map-server) | [**Three.js**](examples/threejs-server) | [**ShaderToy**](examples/shadertoy-server) |
+| [![Sheet Music](examples/sheet-music-server/grid-cell.png "ABC notation to sheet music")](examples/sheet-music-server) | [![Wiki Explorer](examples/wiki-explorer-server/grid-cell.png "Wikipedia link graph visualization")](examples/wiki-explorer-server) | [![Cohort Heatmap](examples/cohort-heatmap-server/grid-cell.png "Customer retention heatmap")](examples/cohort-heatmap-server) |
+| [**Sheet Music**](examples/sheet-music-server) | [**Wiki Explorer**](examples/wiki-explorer-server) | [**Cohort Heatmap**](examples/cohort-heatmap-server) |
+| [![Scenario Modeler](examples/scenario-modeler-server/grid-cell.png "SaaS business projections")](examples/scenario-modeler-server) | [![Budget Allocator](examples/budget-allocator-server/grid-cell.png "Interactive budget allocation")](examples/budget-allocator-server) | [![Customer Segmentation](examples/customer-segmentation-server/grid-cell.png "Scatter chart with clustering")](examples/customer-segmentation-server) |
+| [**Scenario Modeler**](examples/scenario-modeler-server) | [**Budget Allocator**](examples/budget-allocator-server) | [**Customer Segmentation**](examples/customer-segmentation-server) |
+| [![System Monitor](examples/system-monitor-server/grid-cell.png "Real-time OS metrics")](examples/system-monitor-server) | [![Transcript](examples/transcript-server/grid-cell.png "Live speech transcription")](examples/transcript-server) | [![Video Resource](examples/video-resource-server/grid-cell.png "Binary video via MCP resources")](examples/video-resource-server) |
+| [**System Monitor**](examples/system-monitor-server) | [**Transcript**](examples/transcript-server) | [**Video Resource**](examples/video-resource-server) |
+
+### Starter Templates
+
+| | |
+|:---:|:---|
+| [![Basic](examples/basic-server-react/grid-cell.png "Starter template")](examples/basic-server-react) | The same app built with different frameworks — pick your favorite!<br><br>[React](examples/basic-server-react) · [Vue](examples/basic-server-vue) · [Svelte](examples/basic-server-svelte) · [Preact](examples/basic-server-preact) · [Solid](examples/basic-server-solid) · [Vanilla JS](examples/basic-server-vanillajs) |
+<!-- prettier-ignore-end -->
 
 The [`examples/`](https://github.com/modelcontextprotocol/ext-apps/tree/main/examples) directory contains additional demo apps showcasing real-world use cases.
 
-To run all examples together:
+To run all examples:
 
 ```bash
 npm install

examples/basic-server-react/README.md

@@ -1,5 +1,7 @@
 # Example: Basic Server (React)
 
+![Screenshot](screenshot.png)
+
 An MCP App example with a React UI.
 
 > [!TIP]