fix(coding): don't provide worktree root in context

this makes the agent frequently edit files in the wrong worktree.
what the agent doesn't know can't hurt it.

agent/coding_context.py

@@ -711,10 +711,13 @@ def build_coding_workspace_block(cwd: Optional[str | Path] = None) -> str:
             lines.append("- Branch: (detached HEAD)")
 
         # Linked worktree: the per-worktree git dir differs from the shared common dir.
+        # We surface the fact that it's a worktree (so the model knows branches/stashes
+        # are shared state) but deliberately do NOT expose the primary tree path —
+        # giving the model a second absolute path causes it to sometimes run commands
+        # in the wrong directory.
         git_dir, common_dir = _git(root, "rev-parse", "--git-dir"), _git(root, "rev-parse", "--git-common-dir")
         if git_dir and common_dir and Path(git_dir).resolve() != Path(common_dir).resolve():
-            main_tree = Path(common_dir).resolve().parent
-            lines.append(f"- Worktree: linked (primary tree at {main_tree})")
+            lines.append("- Worktree: linked (git state shared with primary tree)")
 
         dirty = [f"{n} {label}" for label, n in (
             ("staged", counts["staged"]), ("modified", counts["modified"]),