docs: address Apr 26 feedback — URL parity, nav reorg, changelog backfill

- Move Developer-tab pages under /developers/* (getting-started/, features/, browser-automations/, credentials/, optimization/, going-to-production/, debugging/, self-hosted/) so URLs mirror Cloud's /cloud/* prefix; add wildcard redirects for the legacy paths and update existing legacy redirects to point at the new locations
- Cloud UI nav: place Workflows above Tasks, promote Workflow Blocks to a top-level group, and add MCP under Integrations
- Developers nav: also promote Workflow Blocks (actions-reference) to a top-level group
- Rewrite cloud/getting-started/core-concepts as a UI tour (no code, dashboard screenshots)
- Changelog: stable id anchors per Update so sidebar links work, and backfill v1.0.8–v1.0.14 plus v1.0.19/v1.0.20 from upstream release notes

docs/cloud/getting-started/run-from-code.mdx

@@ -348,10 +348,10 @@ The response from polling (`get_run`) and webhooks have slightly different struc
 
 ### Artifacts
 
-Every run captures recordings, screenshots, and logs. See [Using Artifacts](/debugging/using-artifacts) for retrieval and the full artifact type reference.
+Every run captures recordings, screenshots, and logs. See [Using Artifacts](/developers/debugging/using-artifacts) for retrieval and the full artifact type reference.
 
 ---
 
 <Note>
-For multi-step automations that chain multiple actions, see [Browser Automation](/browser-automations/overview).
+For multi-step automations that chain multiple actions, see [Browser Automation](/developers/browser-automations/overview).
 </Note>