Implement live accessibility announcements

The board speaks when files change under the user, per DESIGN/10 § Live
board announcements. BoardDiff is the pure snapshot summarizer (identity
sets for cards/lanes added/edited/moved/deleted — ids, not tallies, so
pro-m1's semantic commit engine can build on it; edited = rendered
content only, moved beats edited, implied events don't steal the
subject). BoardAnnouncer is the decision seam: focusOutcome computes the
vanishing-focus sentence and the walk-up-then-sideways recovery (next
lane by order, else previous, board container only when none remain,
never the trash); speech(for:) is the one-sentence precedence ladder —
raised condition > bracket completion > cleared condition > vanished
focus > digest — foreign-only for the last two rungs, so app-mediated
echoes stay silent.

BoardStore.land assembles ReloadFacts and posts exactly one sentence per
reload through the injectable announce outlet (AccessibilityAnnouncer,
medium priority, never interrupting). Selection recovery layers on top
of ItemReferenceSet re-resolution — survivors veto, the emptied
selection lands on the vanished item's lane and re-arms ⌘N's active-lane
memory. performWholesale(announcing:) arms a completion phrase consumed
by the closing reload — nil on every base bracket today; pro-m1 fills
git phrasings. Locks raised outside the reload path (vanished root,
unwritable location) announce through the same ladder, and the banner
strip is a labeled "Board status" container whose row labels are the
announced sentences (AccessibilityPhrases.bannerLabel — one string for
eye and ear).

Announcements classify at reload granularity (WatchOrigin) as a
deliberate interim: DESIGN/02's EchoLedger (per-file classification, the
announcer's specified input, git-free) was scheduled with the
auto-committer that the edition split moved to pro-m1 — filed on the
Redesign board for a ruling. 1533 unit tests green, both schemes build.

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

Kanban/UI/BannerStripView.swift

@@ -61,6 +61,15 @@ public struct BannerStripView: View {
                 }
             }
             .background(.quaternary)
+            // **The strip is an accessibility element** (10-accessibility.md ▸ Live board
+            // announcements, which makes the live-reload-resilience banner one by name). `.contain`
+            // rather than `.combine`: the rows stay individually focusable — each is already one
+            // element with its own tone-prefixed label, and a strip that fused three conditions into
+            // one utterance would bury the lock under the signposts. The group label is what a
+            // VoiceOver user hears on entering it, so "there are conditions here" arrives before the
+            // conditions do.
+            .accessibilityElement(children: .contain)
+            .accessibilityLabel("Board status")
         }
     }
 
@@ -136,10 +145,15 @@ private struct BannerRowView: View {
         .background(row.tone.fill)
         // One element per row, tone included: a VoiceOver user must hear *that* this is an error
         // before hearing what the error is, and colour cannot carry that. The dismiss and Cancel
-        // buttons survive as custom actions of the combined element rather than as separate stops
-        // (10-accessibility.md; the announce-on-appear path arrives with that milestone).
+        // buttons survive as custom actions of the combined element rather than as separate stops.
+        //
+        // The label is composed by `AccessibilityPhrases` rather than spelled here because the two
+        // standing conditions are also *announced* on arrival and clearance (10-accessibility.md ▸
+        // Live board announcements, via `BoardAnnouncer`): the sentence a user hears when the lock
+        // appears and the sentence they read off the row afterwards are one string, or they are two
+        // descriptions of one condition waiting to disagree.
         .accessibilityElement(children: .combine)
-        .accessibilityLabel(Text("\(row.tone.accessibilityPrefix): \(row.headline)"))
+        .accessibilityLabel(Text(AccessibilityPhrases.bannerLabel(tone: row.tone, headline: row.headline)))
     }
 
     @ViewBuilder
@@ -210,16 +224,6 @@ private extension BannerTone {
         case .info: AnyShapeStyle(.background.secondary)
         }
     }
-
-    /// What VoiceOver says before the headline. "Status" rather than "Info" because that is the
-    /// word the platform uses for a non-alarming state announcement.
-    var accessibilityPrefix: String {
-        switch self {
-        case .error: "Error"
-        case .warning: "Warning"
-        case .info: "Status"
-        }
-    }
 }
 
 // MARK: - Previews