docs(landing): document data source blog thumbnails

apps/landing/docs/brand-guide/brand-in-action.md

@@ -61,6 +61,8 @@ Keep the README developer-first. Use badges only for factual status.
 ## Blog
 
 Blog visuals and writing should connect technical ideas to controlled workflows.
+For newly supported data sources, use the repeatable thumbnail pattern in
+`data-source-blog-thumbnails.md`.
 
 Good blog themes:
 

apps/landing/docs/brand-guide/data-source-blog-thumbnails.md

@@ -0,0 +1,123 @@
+# Data Source Blog Thumbnails
+
+Use this pattern for blog posts that announce or explain a newly supported
+connected data source, Source API provider, or integration.
+
+The goal is to make each data source post feel consistent without turning the
+image into a partner lockup or a feature diagram.
+
+## Output
+
+- Size: `1254 x 1254` PNG.
+- Location: `apps/landing/src/assets/blog/<post-slug>-icon.png`.
+- Reference it from the post frontmatter:
+  - `coverImage.src`: `../../assets/blog/<post-slug>-icon.png`
+  - `coverImage.alt`: `OneQuery logo connected to the <provider> logo with a heart symbol.`
+
+## Composition
+
+Use a single centered row:
+
+1. OneQuery logo card.
+2. Solid heart.
+3. Provider logo card.
+
+Do not add titles, subtitles, URLs, arrows, labels, dotted backgrounds, or
+descriptive copy. The article title and description provide that context.
+
+## Canvas
+
+| Element | Value |
+| --- | --- |
+| Canvas | `1254 x 1254` |
+| Background | `#f7f7f5` |
+| Main row vertical center | `627px` |
+| Empty outer padding | At least `250px` on each edge |
+| Total composition width | About `830px` |
+
+Keep the full composition inside the central three-fifths of the canvas. The
+thumbnail should still read clearly when cropped into blog cards or social
+previews.
+
+## Logo Cards
+
+Use equal cards so the OneQuery icon and provider mark have balanced visual
+weight.
+
+| Element | Value |
+| --- | --- |
+| Card size | `270 x 270` |
+| Card fill | `#fbfbfa` |
+| Card stroke | `#111111`, `1.5px` |
+| Card radius | `42px` |
+| Shadow | Very soft alpha-black only; avoid heavy elevation |
+| Gap card to heart | `90px` |
+
+### OneQuery Card
+
+- Use `apps/landing/public/onequery-icon.png`.
+- Center it in the left card.
+- Render at about `162 x 162`.
+- Do not use the OneQuery wordmark.
+- Do not put partner marks inside the OneQuery icon.
+
+### Provider Card
+
+- Use the provider's official logo asset.
+- Preserve its proportions.
+- Prefer a black or monochrome version only when the provider's brand rules
+  allow it.
+- Center it in the right card.
+- Fit it to about `196px` wide, adjusting down when the logo is unusually tall
+  or dense.
+- Do not redraw provider logos with an image generation model; generated logos
+  drift from official marks.
+- Do not recolor partner logos unless their brand rules allow it.
+
+## Heart
+
+Use one centered solid heart between the two cards.
+
+| Element | Value |
+| --- | --- |
+| Heart box | About `122 x 122` |
+| Fill | `#050505` |
+| Shape | Symmetric, standard heart silhouette |
+
+Avoid novelty hearts, lopsided hearts, hand-drawn hearts, and icons with
+uneven bottom points. The heart should read as a neutral connector, not as a
+new brand mark.
+
+## Source Asset Rules
+
+- Use official logo files when available.
+- Keep temporary source logos outside the repo unless they will be reused.
+- Commit only the final thumbnail unless the raw logo asset is already part of
+  the landing asset system.
+- If a provider only has a low-resolution image, get a better official asset
+  before making the thumbnail.
+- If the provider logo includes text as part of the mark, that is acceptable;
+  do not add extra readable text around it.
+
+## Workflow
+
+1. Create or update the blog post under `apps/landing/src/content/blog/`.
+2. Confirm the post slug and target thumbnail path.
+3. Gather the OneQuery icon and official provider logo.
+4. Compose the thumbnail using the geometry above.
+5. Save the final PNG under `apps/landing/src/assets/blog/`.
+6. Inspect the result with `view_image`.
+7. Verify the dimensions with `file`.
+8. Update the post frontmatter if needed.
+9. Run `bun run --cwd apps/landing typecheck` when frontmatter or imports
+   change.
+
+## Checklist
+
+- The final image is exactly `1254 x 1254`.
+- Only two logo cards and one heart are visible.
+- OneQuery and provider logos are official assets, not generated approximations.
+- The cards are the same size and aligned to the same center line.
+- The heart is centered between the cards and has a clean symmetric shape.
+- There is no title, subtitle, URL, arrow, or caption inside the image.
+- The final PNG is referenced by the blog post frontmatter.