docs(blocks): Move block documentation to docs/integrations for separate GitBook space

- Move all block docs from docs/platform/blocks/ to docs/integrations/
- Rename blocks.md to README.md for landing page at /integrations
- Update generate_block_docs.py output path to docs/integrations
- Update workflow files (docs-block-sync, docs-claude-review, docs-enhance)
  to reference new docs/integrations/ path
- Change block doc links to absolute URLs for cross-space compatibility

This separates block/integration documentation into its own GitBook space
to avoid path conflicts with the platform space.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/integrations/README.md

@@ -5,8 +5,8 @@ AutoGPT uses a modular approach with various "blocks" to handle different tasks.
 !!! info "Creating Your Own Blocks"
     Want to create your own custom blocks? Check out our guides:
     
-    - [Build your own Blocks](../new_blocks.md) - Step-by-step tutorial with examples
-    - [Block SDK Guide](../block-sdk-guide.md) - Advanced SDK patterns with OAuth, webhooks, and provider configuration
+    - [Build your own Blocks](https://docs.agpt.co/platform/new_blocks/) - Step-by-step tutorial with examples
+    - [Block SDK Guide](https://docs.agpt.co/platform/block-sdk-guide/) - Advanced SDK patterns with OAuth, webhooks, and provider configuration
 
 Below is a comprehensive list of all available blocks, categorized by their primary function. Click on any block name to view its detailed documentation.