docs: continuous improvement and accuracy fixes

[Tuntii]

Performed a continuous improvement pass on the documentation.

1. Deletions: Removed tuning.md, new_feature.md, and action_pattern.md as they referenced non-existent tools or patterns.
2. File Uploads: Updated the recipe to correctly describe Multipart as buffered (not streaming) and use the correct field.bytes() and field.save_to() APIs. Added warnings about memory usage.
3. WebSockets: Corrected the handler signature to use the WebSocket extractor and the WebSocketStream type in the callback.
4. Learning Path: Added "Mini Projects" to the first three modules to improve the curriculum.
5. Agent Metadata: Updated run report, inventory, and coverage maps.

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PR created automatically by Jules for task 5439372498097529715 started by @Tuntii

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