A picture off the pasteboard becomes a card's file, its hero, or the board's backdrop

⌘V grows an image-data branch, below the app's own clipboard format and refused
outright while a file URL is on the pasteboard: a screenshot or a browser's Copy
Image lands as "Pasted Image.png" in the anchor card's attachments/, through the
very import path Finder file drops and ⇧⌘A take — one bracket, one Finder-style
collision ladder, one set of banners, and the same silence a drop's arrival has.
A card window's ⌘V pastes onto its own card; a focused text field still wins the
selector natively. A file-shaped flavor travels byte for byte, PNG preferred when
several are offered; TIFF and BMP are re-encoded to PNG, being interchange
encodings rather than files anyone wants in a folder.

The hero key gets the setter it was born owing: "Set as Hero" on any image row of
the attachment list, "Remove Hero" on the row that holds it, with menu-bar twins
so the context entry is nobody's only home. It writes as a restyle — one key, one
bracket, one invertible step on the window's own stack — and replaces rather than
refusing, because a card has one hero and the row that has it says Remove instead.

Edit ▸ Paste as Board Background is the same payload's other destination, taking
the existing background.image convention at its word: the picture into the board
folder as "Pasted Background.png", the colour subkey untouched, the generator's
overwrite-our-own-name rule inherited and its echo memo taught to tell the two
producers apart.

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

DESIGN/03-board-ui.md

@@ -27,7 +27,7 @@ Toolbars are **pure enhancement**: every function they host already has a menu i
 
 - Leading icon + title. Two face chips are in scope, both present-only and the same secondary-tinted, decorative styling family: **attachments** (a quiet glyph when the card has files — the title dominates) and **comments** (ruled 2026-08-09, card e729e30a — a quiet bubble glyph plus its count when the card has one or more, joining the attachments chip at the row's trailing edge). Metadata chips (labels/assignees/due) went to the enhanced schema with their fields — out of scope.
 - **No body excerpt, but not "closed with no growth"** (re-settled 2026-08-09 — that old phrasing is retired as stale): the face still never draws a preview of the card's own prose, and that stays closed for good. What *has* grown since is exposure of facts the card already carries structurally, never content: the hero banner (below) and the comments chip both draw from a fact — a named attachment, a folder count — that a sighted glance or a screen reader already had another way to learn, not from anything a body excerpt would have shown.
-- **Hero image** (ruled 2026-08-09): a card whose `hero` key names one of its own attachments (a bare filename — 01-storage-format.md § Frontmatter's card table) draws it as a **banner across the full plate width above the icon-and-title row**, aspect-fill cropped to a fixed em-scaled band (2.75 em — 36pt at the standard body, so it scales with system text size and board zoom like every other face figure). Opt-in and hand-written: **no in-app setter this version** — "Set as Hero" from the attachment row is future work. A key that is absent, malformed, or names a file that is missing, unreadable or not an image renders **exactly as no key at all** — the band has no height until a picture actually decodes, so the degrade is structural rather than a branch. Everything else the face draws is unchanged and sits outside the band: the accent stripe runs the plate's full leading edge over it, the selection and file-hover strokes ring the whole plate, the cut/drag dims cover it, and the drop model registers the plate's real height — a hero card is simply a taller card. The trash draws it too (the one-face rule). The drag replica carries the band when the picture is already decoded, which it is for any card the user can see to drag.
+- **Hero image** (ruled 2026-08-09): a card whose `hero` key names one of its own attachments (a bare filename — 01-storage-format.md § Frontmatter's card table) draws it as a **banner across the full plate width above the icon-and-title row**, aspect-fill cropped to a fixed em-scaled band (2.75 em — 36pt at the standard body, so it scales with system text size and board zoom like every other face figure). Set from the card window's **attachment row context menu** — "Set as Hero" on any image row, "Remove Hero" on the current one (re-ruled 2026-08-09, promoting the day-one "future work" note; 05-card-window.md ▸ Attachments) — and hand-written or agent-written exactly as before. One hero per card: Set on a card that already has one **replaces** it, and the row that holds it shows Remove Hero instead, so there is no Remove-then-Set dance. Image rows only, by extension: offering the row on a `.zip` would let a user set a hero that can never draw. A key that is absent, malformed, or names a file that is missing, unreadable or not an image renders **exactly as no key at all** — the band has no height until a picture actually decodes, so the degrade is structural rather than a branch. Everything else the face draws is unchanged and sits outside the band: the accent stripe runs the plate's full leading edge over it, the selection and file-hover strokes ring the whole plate, the cut/drag dims cover it, and the drop model registers the plate's real height — a hero card is simply a taller card. The trash draws it too (the one-face rule). The drag replica carries the band when the picture is already decoded, which it is for any card the user can see to drag.
 - **Titles are optional at every level.** On cards and lanes, a missing `title` renders as a quiet placeholder ("Untitled", secondary styling) wherever the title would appear. On boards, the fallback is the folder name (sans extension), never "Untitled" — see 01-storage-format.md's board-naming rule; window title and welcome recents show `title` when present, folder name otherwise.
 - Attachments on the face: **the chip only — there is no face carousel** (resettled 2026-07-28, reversing the carry-over): the pathfinder's selection-keyed in-place expansion — compact unselected, media carousel when sole-selected — **proved undesirable and does not carry over**. A card has **one presentation**: selection changes styling (the selection treatment), never geometry, so the masonry never reflows on click and a card face is the same object whatever the selection state. The attachment chip above is the face's whole attachment story; viewing media is the card window's job (⌘↩ / double-click — the attachments section and QuickLook, 05-card-window.md). The earlier 2026-07-28 carousel settlements (metrics, tick paging, clamp, dots, marquee suppression, trash exclusion) are superseded with it — recorded on their Resolved cards.
 
@@ -35,7 +35,7 @@ Toolbars are **pure enhancement**: every function they host already has a menu i
 
 ### Capabilities (settled)
 
-- **`background`** on board / lane / card: a mapping, `{color: …, image: …}`, and only a mapping (settled 2026-08-06 — 01-storage-format.md § Frontmatter; a bare scalar has no reading and paints nothing). `color` is a palette name (kebab-case, hand-editable) or a `#RRGGBB[AA]` hex; either subkey may stand alone. Board color paints the board window's content background (the surface behind and between lanes). **A board's background may also carry an image**: the `image` path is relative to the board root so the picture travels with the document. Color and image both paint the **full window** — the content runs under a transparent title bar, with a frosted strip across the title-bar/toolbar band keeping the chrome legible over them; the extended chrome applies only while the board has a background of its own, and a board without one keeps the standard chrome unchanged. The image draws over the color, scaled to fill and cropped, with the color standing in while it loads or if it can't be read; an unresolvable path paints nothing, the lenient degrade an unrecognized color already gets. **There is no in-app control for the image** — the raw file is the escape hatch (the stance custom hex held until the 2026-08-06 combo reversal; for images it stands) — and **the board-level ink rule still derives from the color reading alone**: an image makes no AA claim (10-accessibility.md), since a picture has no single luminance to threshold against. Lane and card color are **edge accents, not fills** (settled in the pathfinder's treatment shootout — its settings matrix of C-series lane / K-series card variants landed on **C7 · full-column top edge** and **K1 · left edge stripe**): a lane's color paints a full-width band along its top edge, a card's a stripe along its left edge; the surfaces themselves keep the standard chrome, so colored title text never sits on a colored fill.
+- **`background`** on board / lane / card: a mapping, `{color: …, image: …}`, and only a mapping (settled 2026-08-06 — 01-storage-format.md § Frontmatter; a bare scalar has no reading and paints nothing). `color` is a palette name (kebab-case, hand-editable) or a `#RRGGBB[AA]` hex; either subkey may stand alone. Board color paints the board window's content background (the surface behind and between lanes). **A board's background may also carry an image**: the `image` path is relative to the board root so the picture travels with the document. Color and image both paint the **full window** — the content runs under a transparent title bar, with a frosted strip across the title-bar/toolbar band keeping the chrome legible over them; the extended chrome applies only while the board has a background of its own, and a board without one keeps the standard chrome unchanged. The image draws over the color, scaled to fill and cropped, with the color standing in while it loads or if it can't be read; an unresolvable path paints nothing, the lenient degrade an unrecognized color already gets. **The image has exactly one in-app control, and it writes a file rather than browsing for one**: Edit ▸ Paste as Board Background (ruled 2026-08-09) writes the pasteboard's picture into the board folder as `Pasted Background.<ext>` and points `image` at it — the generated-background gesture's shape, minus the colour, because a picture off the pasteboard carries no ground colour to degrade to, so `color` is left exactly as it was. Re-pasting overwrites the board's own file; a file of that name the app did not write is stepped around, Finder-style. There is still **no image picker** — naming a picture that is already somewhere in the folder is the raw file's job, and it stays the escape hatch (the stance custom hex held until the 2026-08-06 combo reversal; for browsing it stands) — and **the board-level ink rule still derives from the color reading alone**: an image makes no AA claim (10-accessibility.md), since a picture has no single luminance to threshold against. Lane and card color are **edge accents, not fills** (settled in the pathfinder's treatment shootout — its settings matrix of C-series lane / K-series card variants landed on **C7 · full-column top edge** and **K1 · left edge stripe**): a lane's color paints a full-width band along its top edge, a card's a stripe along its left edge; the surfaces themselves keep the standard chrome, so colored title text never sits on a colored fill.
 - **The standard chrome is the pathfinder's surface stack** (settled 2026-08-06): the window keeps the neutral system background; every lane wears a quiet quaternary-wash plate (the trash plate's own figure — translucent, so a board-chosen color shows through and the board-level ink rule keeps its premise; opaque under Reduce Transparency, the trash precedent); every card sits on an opaque `controlBackgroundColor` plate — white over the washed lane in light appearance, a step *darker* than the window in dark. One plate value for every face a card draws (resting, replicas, placeholder, arriving), so a card is the same object wherever it renders.
 - **`icon`**: SF Symbol per item with per-level defaults (board `rectangle.split.3x1`, lane `square.stack`, card `doc.text`).
 - **`iconColor`**: resolved — **schema yes, control no**. The field renders when hand-written (tint palette name or hex); the app offers no control for it (Controls below).