[jm-rivera]

Studio cards credit their sources in a short line, and the More Info panel opens with the calculation, credits publishers and cites with a link a reader can follow. Cards drag from their head and frame, so their content can be clicked and selected.

Changes

• Canvas title: the 45-character cut is gone; the title runs to the card filters and opens in full in a hover popup (WorkspaceToolbar.tsx).
• Card source line: "Source: X +N more" with a small More Info mark, no indicator count, and no credit drawn from the attribution label of a described card (sourceLine in src/lib/chat/widgets.ts; CardChrome.tsx).
• Computed cards credit the sources their inputs hold, read from the description's source entries; entries with a content_version are inputs (isInputSource, describedSources).
• More Info: "Calculated as" for quotient and share cards, publisher-first sources, Short and Reference list citations, and a "Create a public link to cite" button that mints a card snapshot once per card version (calculationOf, citeForms in descriptionBlocks.ts; citeLinkKey in infoPanel.ts; CardInfoPanel.tsx; Studio.tsx).
• POST /api/share returns the snapshot's servedAt, so the citation reads "data as of" (src/app/api/share/route.ts, readShareAnswer).
• How this card was made: a step rail of short verb and object rows built from the description's steps (stepRows; ServedStep keeps input and inputs).
• Drag: one press decision for card drag and board pan; mouse presses on the head or frame drag after 4 px, presses on content click and select text, and touch or read-only canvases still pan (src/components/organisms/Studio/canvas/cardPress.ts, useCardDrag.ts, usePan.ts).

Notes for reviewers

• Computed cards name their publishers once dfo-apis serves credited source entries; until then a computed card reads "Source: DFO calculation".
• description-computed-quotient.json stays byte-identical to the dfo-spec-kit vector; the credited shape lives in the local description-computed-quotient-credited.json.
• The source line keeps "Source:" whole with :has(); older browsers let it shrink.
• The motion-kit films reference CardChrome and Whiteboard classes this change renames or removes, and need recapturing.

Testing: pnpm lint, pnpm lint:css, pnpm typecheck, pnpm test (2,212 pass on this layer) and pnpm build pass. Before and after screenshots of a seeded conversation are below.

Screenshots

Before is origin/dev (b91925c) and after is this branch, at 1440 by 900. Both ran against a local Postgres seeded with the same two saved conversations, loaded at /studio/.

Change	Before	After
Canvas title: more of the long title shows before the ellipsis
Hovering the title shows the full text in a tooltip	Not present
Source line on a bar card: one line reading "Source: ..." with an info icon, beside the Built with DFO mark
Source line on a stat card: one line with the mark in place of a two-line footer that clipped it
More Info, top: a Calculated as block, and a Short and Reference list toggle for the citation
More Info, How this card was made: the steps read as a timeline in place of three paragraphs
Drag from the title row: the card moves in both builds
Press on a legend and drag: the card stays in place and the legend text is selected
Press on a table cell and drag: the card stays in place and the cell text is selected