feat(chat): default scoped project conversations to workspace writes

[huangruiteng]

Host-declared project workspaces and new Codex project App bindings default to workspace_write, with an explicit read-only option. The typed context owner derives the real sandbox for start and exact-thread resume; project rules and skills govern requested edits. This grants neither manager identity nor peer delegation. Existing read-only App grants remain read-only unless deliberately reconfigured.

Integrated #5546 at a8fba934a507e1ef0ac2cebbaf9868095d60d00b through an append-only merge, preserving original branch history and the merged #5540 workspace design. The base-relative diff remains limited to this capability.

Validation on a1984becf42dd9bf76f7c7f3ab6ae66efb04aa89: 14 project/binding/status Python tests, Core types, packaged Chat build and three UI contracts passed. The actual packaged unified workspace scope read back workspace_write and displayed “read and write”; the obsolete separate Project settings panel stays removed. Private settings retain an explicit read-only choice.

The predecessor’s committed-commission recovery fix is retained. Current-head CI and maintainer review remain required; old-head evidence is historical. This is a source candidate, not installed promotion or proof of live Operations Agent delegation, independent host browser reading, or permission callbacks. No architecture thresholds were raised for this integration.

The registry IO census was regenerated and validated on this exact stack state after parent integration; no unclassified site remains.

[mergify]

This pull request has merge conflicts with main and cannot be merged
until they are resolved. Please rebase or merge the base branch, @huangruiteng.

Choose the remote for the base repository, not an out-of-date fork.
For a fork clone, first inspect git remote -v; upstream must point
to https://github.com/loopx-project/loopx.git. If it is absent, add it
with git remote add upstream https://github.com/loopx-project/loopx.git.
Then run:

git fetch upstream
git rebase upstream/main
# Resolve each conflict, git add the resolved files, then git rebase --continue.
git push --force-with-lease origin HEAD

For a same-repository clone whose origin points to
https://github.com/loopx-project/loopx.git, use origin instead of
upstream for fetch/rebase. If you prefer merging the base, use
git merge <base-remote>/main and push normally.

Keep the DCO Signed-off-by trailer on every commit when you rebase.
https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork