Print boards and cards with configurable components and named print profiles

⌘P had no story: KanbanApp removed the platform's Print row outright on
11-command-nexus.md's "No Print story in v1 (⌘P unused)" line. That line
retires. File ▸ Print… now prints the board in front — lanes left to right,
each lane's cards top to bottom, as a linear document rather than a picture
of the strip — or, from a card window, that card. The trash is unreachable
by construction: it is a sibling container of `lanes`, not a lane.

The rules live in a pure layer nothing AppKit can reach. `PrintOptions` is
one Codable value carrying the printing card's five bullets — which
components (title, icon+labels line, rendered body, comments off by default
with either reading order), page breaks, one base face and size every other
size derives from, and a toggleable running head and foot. `PrintSource` is
what is being printed, frozen at ⌘P so the panel's repeated relayouts and a
board reloading underneath cannot disagree. `PrintDocumentBuilder` turns the
pair into a block list, which is where every decision a rendered page hides
becomes something a test can hold: component order, comment ordering, and
page-break markers that are markers rather than whitespace. Empty is empty
all the way up — a card with nothing to print consumes no page break, and a
lane whose cards all dropped out takes its heading with it.

A page break is a pagination fact, not a spacing one. TextKit has no
page-break character, so `PrintDocumentView` splits the document into
sections at its breaks and flows each into as many page-sized text
containers as it needs: a container boundary *is* a sheet boundary, at any
paper size with any margins. Bodies come from the app's one Markdown pass —
`BodyMarkup.parse` into `BodyMarkupRenderer` — re-faced run by run so the
chosen family reaches the text and fixed-pitch code keeps its own, and drawn
under a forced light appearance so the card window's dynamic label colours
do not print white.

Options ride in the print panel's own accessory rather than a pre-flight
sheet of ours, which buys the system's live preview of the real paginated
document; the preview refreshes through one KVO revision counter rather than
thirteen mirrored properties. Profiles persist app-side in UserDefaults,
never in board files — a print profile is how this user likes to read, not
what a board is (`BoardZoomStore`'s argument). A name is a profile's
identity, folded case-insensitively; "Last Used" is reserved in every
spelling, kept out of the stored list, and captured when an operation
actually ran, so a cancelled print rewrites nothing. Both decoders are
total: one unrecognized key must not cost a user every profile they saved.

DESIGN/11-command-nexus.md gains the Print row and loses the sentence
saying it would never have one.

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

Kanban/App/CardWindowHost.swift

@@ -285,6 +285,10 @@ struct CardWindowHost: View {
     /// reason: two card windows on one board have two different selections, and the menu bar reaches
     /// the frontmost one through the focus system.
     @State private var attachments = CardAttachments()
+    /// This window's printable subject — the card, its lane, its board and its thread, as File ▸ Print…
+    /// needs them (`CardPrintSubject`). Window-scoped for `CardBodyPresentation`'s reason: two card
+    /// windows are two documents, and the menu bar reaches the frontmost one through the focus system.
+    @State private var cardPrint = CardPrintSubject()
     /// This window's thumbnail memory. Held here rather than in the section so it survives every
     /// snapshot the store applies — a cache that died with the view would regenerate every thumbnail
     /// on every reload (`AttachmentThumbnailCache`).
@@ -381,6 +385,9 @@ struct CardWindowHost: View {
             // know a card window is in front at all (11-command-nexus.md scopes all three to the card
             // window).
             .focusedSceneValue(\.cardComments, session.comments)
+            // File ▸ Print… (⌘P) reaches the frontmost card window the same way — the card-window scope
+            // of a row the board window answers with its whole board (11-command-nexus.md).
+            .focusedSceneValue(\.cardPrint, cardPrint)
             // The raw-source outlet's detailed alert, presented over this window — a validation
             // refusal on Apply, or a file that could not be opened as source. It hangs *here* rather
             // than inside the editor because the second of those fires while source mode is still
@@ -473,6 +480,21 @@ struct CardWindowHost: View {
                 // would open nothing.
                 attachments.cardFolder = folder
                 session.comments.cardFolder = folder
+                cardPrint.cardFolder = folder
+            }
+            // **File ▸ Print…'s subject, re-derived from every snapshot** for the folder's and the
+            // announcer's reason: a card renamed, restyled, relabelled or moved to another lane prints as
+            // it is now (`CardPrintSubject`). The thread is a closure rather than a value, so ⌘P reads the
+            // comments at the moment it is pressed rather than whatever the pane last saw.
+            .onChange(of: placement.card, initial: true) { _, card in
+                cardPrint.card = card
+                cardPrint.readThread = { store.commentThread(inCard: card.id) }
+            }
+            .onChange(of: placement.lane.title.value, initial: true) { _, title in
+                cardPrint.laneTitle = title
+            }
+            .onChange(of: AppModel.displayName(of: store), initial: true) { _, title in
+                cardPrint.boardTitle = title
             }
             // The announcer's subject, re-derived from every snapshot for the folder's reason: a card
             // renamed mid-session is announced under its new name ("New comment on '⟨card⟩'").