Give the popover git slot the contextual Pro posture

12's settled ruling supersedes the m4 placeholder: on an ordinary board
the git section is simply absent — the popover is complete in itself —
and on a board carrying an inert .git it shows only the calm one-line
note, 'This board has a git history. Lanework Pro works with it.' The
detection is a pure one-line seam checking the board root at popover
open, deliberately non-live: .git is filtered from the watch by design,
so there is no reload to hang a live fact off, and a quiet signpost
self-corrects on next open.

Claude-Session: https://claude.ai/code/session_01SR4XGjmBE16ZUYWpfFHXwY

KanbanTests/BoardInfoPopoverTests.swift

@@ -0,0 +1,32 @@
+import Foundation
+import Testing
+@testable import Kanban
+
+/// **The board popover's git-note detection** (12-editions.md § Base and `.git`, ruled 2026-07-27):
+/// base's whole git story is one line, shown only on a board that carries an inert `.git`. The seam
+/// that decides *whether* to show it — `BoardGitNote.hasGitDirectory(at:)` — is a pure, read-only
+/// `FileManager` check, pinned here against real bytes on disk. Everything else about the note (its
+/// wording, its placement in `BoardInfoView`) is SwiftUI rendering and deliberately untested.
+struct BoardInfoPopoverTests {
+
+    @Test("A board with a .git at its root reports true")
+    func trueForABoardWithGit() throws {
+        let fixture = try WriterFixture()
+        defer { fixture.tearDown() }
+
+        try fixture.item("", Item.board)
+        try fixture.file(".git/HEAD", Data("ref: refs/heads/main\n".utf8))
+
+        #expect(BoardGitNote.hasGitDirectory(at: fixture.root))
+    }
+
+    @Test("An ordinary board with no .git reports false")
+    func falseForAnOrdinaryBoard() throws {
+        let fixture = try WriterFixture()
+        defer { fixture.tearDown() }
+
+        try fixture.item("", Item.board)
+
+        #expect(!BoardGitNote.hasGitDirectory(at: fixture.root))
+    }
+}