fix(git-status): landing fixes (#537)

- A cached list of repositories below a folder is re-checked against the
  Docker case workspaces as they are now, so a repository linked as a Docker
  workspace within the 30 s list cache is no longer inspected.
- A diff past runGit's 8 MB output bound is cut short from git's partial
  output instead of failing with a 500.
- The browser test waits for its slow route handler on unroute
  (unrouteAll behavior 'wait'), so a late route.continue() cannot fail the run.
- "Upstream is gone" now reads "Upstream not on remote", true for a branch
  that was never pushed as well as one deleted on the remote; docs mirrored.
- The diff route checks the repository against the workspace's own cached
  repository list (findWorkspaceRepo) and refreshes only that repository,
  instead of a fresh status of every repository in the folder.
- CLAUDE.md: a Key Patterns entry for the git read surface and its rules.
- The enclosing repository is identified with one cached rev-parse before
  any full status, so an unrelated repository above the workspace costs one
  process and its failure no longer hides the repositories below.
- Wiki: the bottom-bar indicator moves out of the header-controls table.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/wiki/The-Dashboard.md

@@ -119,12 +119,18 @@ The right side of the header. Almost all of these are off until you enable them
 | Multi-monitor          | Off, macOS         | Opens a window spanning every display.                                            |
 | Split                  | Off, desktop only  | View a second session beside the active one, with a draggable divider.           |
 | Tunnel indicator       | When a tunnel runs | Cloudflare tunnel status.                                                        |
-| Git status (bottom bar) | Off               | Right of the bottom bar: uncommitted and unpushed work for the active session. Click it for the Git window. See [Working With Files](Working-With-Files#git-changes). |
 | Admin panel            | Multi-user only    | User administration.                                                              |
 
 New header controls never appear on phones. Phone layout is deliberately minimal and is
 covered in [Mobile Guide](Mobile-Guide).
 
+## Bottom bar
+
+**Git status** sits at the right of the bottom bar and shows the active session's uncommitted
+and unpushed work. It is off by default and per device: turn it on in **App Settings → Header &
+Panels → Bottom bar**. Click it for the Git window. See
+[Working With Files](Working-With-Files#git-changes).
+
 ## Connection state
 
 The dot in the header is the quick read. Two louder surfaces exist because a cached page