docs: Update Git Worktrees documentation to use placeholder for default branch reference

Author: MariusStorhaug

src/docs/Ways-of-Working/Git-Worktrees.md

@@ -9,22 +9,22 @@ All repositories are set up as **bare clones with worktrees**. This enables para
 | Only one branch checked out at a time        | Each issue gets its own worktree — parallel by default    |
 | Switching branches requires clean state      | Worktrees are independent — no stashing or committing WIP |
 | Agent work blocks human work on same repo    | Different worktrees, no interference                      |
-| Default branch gets dirty during development | `main/` worktree is always a clean reference              |
+| Default branch gets dirty during development | `<default>/` worktree is always a clean reference         |
 
 ## Repository layout
 
 ```text
 <repo-root>/
 ├── .bare/              # bare git data (the actual repository)
 ├── .git                # file containing: gitdir: ./.bare
-├── main/               # worktree: default branch (always clean, never worked in directly)
+├── <default>/          # worktree: default branch (always clean, never worked in directly)
 ├── 42-add-pagination/  # worktree: issue #42 in progress
 └── 99-fix-null-ref/    # worktree: issue #99 in progress
 ```
 
 - **`.bare/`** — the shared git object store. All worktrees share this.
 - **`.git`** — a file (not a directory) that points git tooling to `.bare/`.
-- **`main/`** — the default branch worktree. Kept as a clean reference. Used for diffing, reading docs, running comparisons. Never directly committed to.
+- **`<default>/`** — the default branch worktree (e.g. `main` or `master`). Kept as a clean reference. Used for diffing, reading docs, running comparisons. Never directly committed to.
 - **`<N>-<slug>/`** — one worktree per issue in flight. Named by issue number and a short slug. Branch name matches the folder name.
 
 ## Remotes
@@ -70,8 +70,15 @@ git -C .bare config remote.origin.fetch '+refs/heads/*:refs/remotes/origin/*'
 # Fetch remote branches
 git -C .bare fetch origin
 
+# Determine the default branch
+$defaultBranch = git -C .bare symbolic-ref HEAD | ForEach-Object { $_ -replace 'refs/heads/', '' }
+
 # Create the default branch worktree
-git -C .bare worktree add ../main main
+git -C .bare worktree add "../$defaultBranch" $defaultBranch
+
+# Set upstream tracking (prevents "Publish Branch" prompt in VS Code)
+git -C .bare config "branch.$defaultBranch.remote" origin
+git -C .bare config "branch.$defaultBranch.merge" "refs/heads/$defaultBranch"
 ```
 
 > The [Checkout-GitHubRepo](https://github.com/MariusStorhaug/.dev/blob/main/.github/Checkout-GitHubRepo.ps1) script automates this for all repositories.
@@ -80,7 +87,12 @@ git -C .bare worktree add ../main main
 
 ```powershell
 # From the repo root (where .bare/ lives)
-git -C .bare worktree add ../42-add-pagination -b 42-add-pagination main
+$defaultBranch = git -C .bare symbolic-ref HEAD | ForEach-Object { $_ -replace 'refs/heads/', '' }
+git -C .bare worktree add ../42-add-pagination -b 42-add-pagination $defaultBranch
+
+# Set upstream tracking (prevents "Publish Branch" prompt in VS Code)
+git -C .bare config branch.42-add-pagination.remote origin
+git -C .bare config branch.42-add-pagination.merge refs/heads/42-add-pagination
 
 # Open in VS Code
 code 42-add-pagination
@@ -94,6 +106,9 @@ Then follow the normal Implement flow: initial commit → push → draft PR →
 # Remove the worktree
 git -C .bare worktree remove 42-add-pagination
 
+# Delete the local branch ref
+git -C .bare branch -D 42-add-pagination
+
 # Prune if needed (removes stale worktree references)
 git -C .bare worktree prune
 ```