Comments, phase 3 — search, the thread find, announcements, and a11y

Board search reaches comment bodies through a search-owned transient
index: the first live-query keystroke sweeps comments/*/index.md
off-actor (.draft and comments/.trash excluded), keystrokes re-filter
in memory, the index discards on clear — the snapshot stays O(cards).
⌘F routes by focus: the comments pane gets an app-owned find bar
spanning the whole rendered thread (next/prev cross rows with
wraparound); body and composer keep NSTextFinder; Find Next/Previous
graduate from FutureCommands. Foreign comment changes speak
path-shaped beside the announcer's ladder ("New comment on 'X'",
plural folds), narrowed by EchoLedger receipts consumed through
CommentPath.classify — and that read fixed a latent footprint bug
where a comment receipt resolved against the card's attachment
listing, read .absent, and classified the user's own write as
foreign. The pane completes its a11y story: flattened comment
elements with Edit/Delete/Reveal custom actions (un-flattening
during inline edit), phrase-table vocabulary, labeled composer and
sort control, and an audit over the open pane on a comment-seeded
fixture (runnable only where automation permission exists).

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

Kanban/UI/Card/CommentComposerView.swift

@@ -88,7 +88,11 @@ struct CommentAuthoringSurface<Actions: View>: View {
                 onCommandReturn: onCommandReturn,
                 onEscape: onEscape,
                 onBlur: onBlur,
-                focusRequest: focusRequest
+                focusRequest: focusRequest,
+                // Both authoring surfaces report themselves to the pane's focus register, which is
+                // what routes ⌘F here to the editor's own find bar rather than to the thread's
+                // (05 ▸ Preview; `CardWindowFind.route`).
+                focus: comments
             )
             .frame(height: height)
 
@@ -124,7 +128,7 @@ struct CommentAuthoringSurface<Actions: View>: View {
         .buttonStyle(.plain)
         .disabled(!comments.isEditable)
         .help("Attach Files…")
-        .accessibilityLabel("Attach Files")
+        .accessibilityLabel(AccessibilityPhrases.commentAttachFilesLabel)
     }
 }
 
@@ -183,7 +187,10 @@ struct CommentComposerView: View {
                 .controlSize(.small)
                 .disabled(!comments.isEditable || !session.canPost)
         }
-        .accessibilityLabel("Add a comment")
+        // "The composer is a labeled text field (⌘↩ posts)" — 10-accessibility.md ▸ Comments. The
+        // label is the placeholder's own sentence, so what a sighted user reads in the empty editor
+        // and what VoiceOver announces are the same invitation.
+        .accessibilityLabel(AccessibilityPhrases.commentComposerLabel)
     }
 
     /// Post, then re-read: the rename moved a folder into the thread, and the pane shows the thread.