chore(server): rename Session to WebSession

[enyst]

(OpenHands-GPT-5 speaking)

Minimal, risk-averse cleanup to clarify naming before broader refactor:

Summary

• Rename the webserver-bound Session class to WebSession.
• Preserve full backward compatibility via:
  • openhands.server.session.init exporting both WebSession and Session (alias)
  • in-file alias at the bottom of session.py: Session = WebSession
• Update only server-side imports in conversation managers to reference WebSession as Session (no behavior change)
• Add concise docstring to WebSession for quick comprehension by humans and LLMs

Why now

• Aligns terminology ahead of the unified sessions refactor so the existing class reads as explicitly web-bound.
• Keeps CI-safe: no runtime behavior changes, unit tests that import Session continue to work due to aliases.

Files touched

• openhands/server/session/session.py
  • class Session -> class WebSession
  • add class docstring
  • add alias at EOF: Session = WebSession
• openhands/server/session/init.py
  • export both names; keep Session as alias for BC
• openhands/server/conversation_manager/standalone_conversation_manager.py
  • import WebSession as Session (minimal import change)
• openhands/server/conversation_manager/docker_nested_conversation_manager.py
  • import WebSession as Session (minimal import change)

Notes

• No external API or behavior change; pure rename with aliases.
• Tests that import Session directly (e.g., tests/unit/server/session/test_session.py) will continue to pass.

Follow-ups

• Subsequent PRs will introduce a neutral ConversationRuntimeContext and mode adapters, as discussed in PR unify session/conversation architecture; neutral Conversation facade #10424.

Refs

• Issue Analyze concept/consistency of sessions across the app #10336 for context.

---

To run this PR locally, use the following command:

GUI with Docker:

docker run -it --rm   -p 3000:3000   -v /var/run/docker.sock:/var/run/docker.sock   --add-host host.docker.internal:host-gateway   -e SANDBOX_RUNTIME_CONTAINER_IMAGE=docker.all-hands.dev/all-hands-ai/runtime:63ba3b4-nikolaik   --name openhands-app-63ba3b4   docker.all-hands.dev/all-hands-ai/openhands:63ba3b4

CLI with uvx:

uvx --python 3.12 --from git+https://github.com/All-Hands-AI/OpenHands@chore/websession-alias-docs openhands

[openhands-ai]

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