loop: always use branch sketch-wip in innie

Modify innie sketch to always create and work on a dedicated 'sketch-wip'
branch for all git operations, pushing this branch to outie instead of
pushing HEAD directly.

Having a dedicated branch name makes it clearer how to operate
inside the container, for both humans and sketch.
It also prevents the container from pushing whatever transient
commits occur while sketch does (say) a bisection or other git work.
It should also prevent sketch from constantly spinning up new
branches as it starts new tasks in a long conversation.

I'd rather have called the branch 'sketch' instead of 'sketch-wip',
but that conflicts with all the branches called 'sketch/foo'. Alas.

This was mostly written by Josh, but I made it work whether or not
sketch-wip already exists as a branch.

Co-Authored-By: sketch <hello@sketch.dev>
Change-ID: s4ea6db2873a60129k
diff --git a/claudetool/about_sketch.txt b/claudetool/about_sketch.txt
index 63ab2e0..32a7814 100644
--- a/claudetool/about_sketch.txt
+++ b/claudetool/about_sketch.txt
@@ -52,16 +52,17 @@
 {{ $branch = .Branch}}
 {{ end }}
 
-- Sketch is trained to make git commits. When those happen, they are automatically pushed to the git repository where you started sketch with branch names `sketch/*`.
+- Sketch is trained to make git commits to the sketch-wip branch in the container. When those happen, 
+  they are automatically pushed to the git repository where you started sketch, with branch names like `sketch/*` or `username/sketch/*`.
 - Use `git branch -a --sort=creatordate | grep sketch/ | tail` to find Sketch branches.
-- The UI keeps track of the latest branch it pushed and displays it prominently.
+- The UI keeps track of the latest commit it pushed and display the branch name for it prominently in the top bar.
 - You can integrate Sketch's changes using:
   ```
   git cherry-pick $(git merge-base origin/main {{$branch}})
   git merge {{$branch}}
   git reset --hard {{$branch}}
   ```
-- You can ask Sketch to `git fetch sketch-host` and rebase onto another commit.
+- You can ask Sketch to `git fetch origin` and rebase its sketch-wip branch onto another commit.
 - Sketch is good at helping you rebase, merge/squash commits, rewrite commit messages, and other Git operations.
 
 ## Reviewing Diffs