docs(blocks): complete block documentation migration cleanup

Move remaining block docs to block-integrations/ subdirectory:
- Delete old docs from docs/integrations/ root
- Add new docs under docs/integrations/block-integrations/
- Add guides/ directory with LLM and voice provider docs
- Update SUMMARY.md with correct navigation structure

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

docs/integrations/block-integrations/linear/projects.md

@@ -0,0 +1,40 @@
+# Linear Projects
+<!-- MANUAL: file_description -->
+Blocks for searching and managing Linear projects.
+<!-- END MANUAL -->
+
+## Linear Search Projects
+
+### What it is
+Searches for projects on Linear
+
+### How it works
+<!-- MANUAL: how_it_works -->
+This block searches for projects in Linear using a text query. It queries the Linear GraphQL API to find projects matching the search term.
+
+Returns a list of projects with their details for further use in workflows.
+<!-- END MANUAL -->
+
+### Inputs
+
+| Input | Description | Type | Required |
+|-------|-------------|------|----------|
+| term | Term to search for projects | str | Yes |
+
+### Outputs
+
+| Output | Description | Type |
+|--------|-------------|------|
+| error | Error message if the operation failed | str |
+| projects | List of projects | List[Project] |
+
+### Possible use case
+<!-- MANUAL: use_case -->
+**Project Discovery**: Find projects by name to use in issue creation or queries.
+
+**Portfolio Overview**: Search for projects to build portfolio dashboards.
+
+**Dynamic Forms**: Populate project dropdowns in custom interfaces.
+<!-- END MANUAL -->
+
+---