Denial is not absence — detection learns the unverifiable answer 06 ruled for it

Claude-Session: https://claude.ai/code/session_014PtZdPwqZuqEDLc6wZMtEy

Kanban/Git/GitRepository.swift

@@ -93,17 +93,20 @@ enum GitRepository {
     /// git's since 2026-07-31, so it is almost always already there; when it is not, seeding it here
     /// puts it *in* the initial commit rather than after it (`seedGitignoreIfAbsent`).
     ///
-    /// **Create re-runs full detection and refuses anything but mode none** (06 ▸ Rules ▸ Detection,
-    /// ruled 2026-07-31): "as hardening, add-git's create re-runs full detection and refuses unless it
-    /// reads clean none, so the forbidden nested init is impossible even on a raced or stale read."
+    /// **Create re-runs full detection and refuses anything but clean mode none** (06 ▸ Rules ▸
+    /// Detection, ruled 2026-07-31): "as hardening, add-git's create re-runs full detection and
+    /// refuses unless it reads clean none, so the forbidden nested init is impossible even on a
+    /// raced or stale read."
     ///
     /// The caller (`HistoryStore.addGit`) has already established mode `none` from the mode it
     /// detected at board open, which can be minutes old — a `git init` in a terminal at the board root
     /// *or anywhere above it* between the two would otherwise slip past a root-only check and
     /// initialize a repository inside the user's, which is the one init 06 forbids outright. The whole
     /// walk runs again here, at the moment of the write, so the refusal is structural rather than
-    /// probable. (Detection has no *unverifiable* answer yet — 06's denial-is-not-absence distinction
-    /// is not built — so "clean none" is spelled `.none` for now.)
+    /// probable. **`.unverifiable` refuses too** — a denied ancestor check can never be told apart
+    /// from a repository actually being there, so only a genuinely clean `.none` reading proceeds; a
+    /// stale `.none` that has since become unverifiable is refused exactly like one that has since
+    /// become repo-nested.
     ///
     /// Returns the branch the root commit landed on, which is the popover's display line.
     nonisolated static func create(at boardRoot: URL) -> Result<String, GitOperationFailure> {
@@ -122,6 +125,11 @@ enum GitRepository {
                 operation: operation,
                 message: "this board lives inside a repository; Lanework leaves it to that repository"
             ))
+        case .unverifiable:
+            return .failure(GitOperationFailure(
+                operation: operation,
+                message: "this board's surroundings could not be fully checked, so Lanework will not add a repository here"
+            ))
         }
 
         let gitDirectory: URL