Fix review 646 blockers B1-B7 for cross-repo canonical roots (#973)

namespace_workspace_binding.py

@@ -189,23 +189,23 @@ def verify_git_common_directory_membership(
             real_common = os.path.realpath(common_dir)
             canonical_git = os.path.realpath(os.path.join(real_root, ".git"))
 
-            if real_common in (canonical_git, real_root) or os.path.dirname(real_common) == real_root:
+            if real_common in (canonical_git, real_root):
                 return True, None
             return (
                 False,
                 f"workspace '{real_ws}' git common directory '{real_common}' does not match "
                 f"canonical repository root '{real_root}' (.git at '{canonical_git}')"
             )
-    except Exception:
-        pass
-
-    if amw.is_path_under_branches(real_ws, real_root):
-        return True, None
-
-    return (
-        False,
-        f"workspace '{real_ws}' does not belong to canonical repository root '{real_root}'"
-    )
+        else:
+            return (
+                False,
+                f"workspace '{real_ws}' is not a valid git repository or git rev-parse failed"
+            )
+    except Exception as exc:
+        return (
+            False,
+            f"failed to inspect git common directory for workspace '{real_ws}': {exc}"
+        )
 
 
 def resolve_namespace_mutation_context(
@@ -313,6 +313,8 @@ def resolve_namespace_mutation_context(
         "canonical_repo_root": canonical_root,
         "roots_aligned": roots_aligned,
         "canonical_root_assessment": crr_assessment,
+        "expected_slug": expected_slug,
+        "remote": remote,
     }
     if durable is not None:
         result["author_worktree_resolution"] = durable
@@ -324,6 +326,15 @@ def resolve_namespace_mutation_context(
         result["author_worktree_reasons"] = list(durable.get("reasons") or [])
         result["author_worktree_blocker_kind"] = durable.get("blocker_kind")
         result["operator_recovery"] = durable.get("operator_recovery")
+    else:
+        path_exists = os.path.exists(workspace)
+        result["path_exists"] = path_exists
+        result["in_git_worktree_list"] = (
+            amw.path_in_git_worktree_list(workspace, canonical_root)
+            if path_exists
+            else False
+        )
+        result["bound_worktree_missing"] = not path_exists
     return result
 
 
@@ -456,8 +467,8 @@ def format_namespace_workspace_binding_error(
 def assess_namespace_mutation_workspace(
     *,
     role_kind: str,
-    worktree_path: str | None,
-    worktree: str | None,
+    worktree_path: str | None = None,
+    worktree: str | None = None,
     process_project_root: str,
     env: dict[str, str] | os._Environ | None = None,
     session_lease_worktree: str | None = None,
@@ -509,14 +520,16 @@ def assess_namespace_mutation_workspace(
     if crr_reasons:
         reasons.extend(crr_reasons)
 
-    if not ctx.get("roots_aligned"):
-        if not crr_reasons:
-            reasons.append(
-                f"unsafe_process_root_workspace_alignment: process root '{process_root}' "
-                f"and canonical root '{ctx['canonical_repo_root']}' disagree"
-            )
+    path_exists = ctx.get("path_exists")
+    if path_exists is None:
+        path_exists = os.path.exists(mutation_workspace)
 
-    if os.path.exists(mutation_workspace):
+    if not path_exists:
+        if role != "author":
+            reasons.append(
+                f"{role} mutation blocked: configured workspace directory '{mutation_workspace}' does not exist (nonexistent worktree)"
+            )
+    else:
         valid_common, common_err = verify_git_common_directory_membership(
             mutation_workspace, ctx["canonical_repo_root"]
         )
@@ -539,26 +552,27 @@ def assess_namespace_mutation_workspace(
             )
             if branches["block"]:
                 reasons.extend(branches["reasons"])
-    elif (
-        role == "reviewer"
-        and mutation_workspace == process_root
-        and not amw.is_path_under_branches(mutation_workspace, ctx["canonical_repo_root"])
-    ):
-        reasons.append(
-            f"{role} mutation blocked: workspace is the stable control checkout; "
-            f"create or reconnect to a session-owned worktree under branches/ "
-            f"or set {ROLE_WORKTREE_ENVS.get(role, ACTIVE_WORKTREE_ENV)} / "
-            f"{ACTIVE_WORKTREE_ENV}"
-        )
-    elif (
-        role in {"reviewer", "merger"}
-        and mutation_workspace != process_root
-        and not amw.is_path_under_branches(mutation_workspace, ctx["canonical_repo_root"])
-    ):
-        reasons.append(
-            f"{role} mutation blocked: workspace '{mutation_workspace}' is not under "
-            f"'{ctx['canonical_repo_root']}/branches/'"
-        )
+    elif role in {"reviewer", "merger"}:
+        if mutation_workspace == process_root and not amw.is_path_under_branches(mutation_workspace, ctx["canonical_repo_root"]):
+            reasons.append(
+                f"{role} mutation blocked: workspace is the stable control checkout; "
+                f"create or reconnect to a session-owned worktree under branches/ "
+                f"or set {ROLE_WORKTREE_ENVS.get(role, ACTIVE_WORKTREE_ENV)} / "
+                f"{ACTIVE_WORKTREE_ENV}"
+            )
+        elif mutation_workspace != process_root and not amw.is_path_under_branches(mutation_workspace, ctx["canonical_repo_root"]):
+            reasons.append(
+                f"{role} mutation blocked: workspace '{mutation_workspace}' is not under "
+                f"'{ctx['canonical_repo_root']}/branches/'"
+            )
+
+        if path_exists and amw.is_path_under_branches(mutation_workspace, ctx["canonical_repo_root"]):
+            in_list = ctx.get("in_git_worktree_list")
+            if in_list is False:
+                reasons.append(
+                    f"{role} mutation blocked: workspace '{mutation_workspace}' is under branches/ "
+                    f"but is not registered in git worktree list for '{ctx['canonical_repo_root']}'"
+                )
 
     block = bool(reasons)
     return {