A settled top-level `read_image` call printed its raw attachment object as
literal text in the tool card — `{"type":"image","attachment":{…}}` —
instead of the image, because no presentation metadata told a client card
how to present the reference and the tool-card layer had no image concept.
Host: `read_image` declares an `output.presentationMeta` persisting
`{ path }` only. The attachment reference deliberately lives in the
settled result content — the single record a `tools/post-execute`
replacement rewrites — not in `meta`; the id is opaque and
provider-owned, checked for existence only.
Client: `imageCardModel` derives the card from the call head, the meta
path, the result's own image block, and a shape-matched envelope. ToolRow
gains an `image` card slot; the `read_image` toolview declares the
Tool-owned `tool.call.images` slot as its child and dispatches the
gallery through it. ui-chat down-threads the session-authorized loader
(`ChatNodeOwnerProps.loadImage`), so the tool layer supplies only derived
references plus the loader and never imports an attachment
implementation; ui-attachment fills the slot with its message gallery
renderer. The card keeps the envelope text below the gallery for the
no-attachment-plugin deployment. An image-bearing tool registers a keyed
toolview; the generic fallback keeps its flattened text. `read_image`
joins the read variant with its own locale title key; both rows share
`read-family-row.tsx`.
Verification: `read-image.spec.ts` (metadata projection, envelope by
shape, reference narrowing, real-execution round trip, rejection
branches incl. non-digest ids), `image-card.client.spec.tsx` (derivation,
row render site dispatching the slot, keyed registration with the
child-slot declaration, empty-slot fallbacks, media-type enum), keyless
snapshots (`read-image-gif` added; read-image/-dimension/-reencode
updated to the `{path}` meta), five injected-defect negative controls,
and a demo GIF recorded from this PR's head through the official
image-capable model.
The provider-card seat's keyConfigured now derives from the reference the
page would use — the profile's apiKeyEnv, or the page's derived
<ROUTE>_API_KEY while the profile names none — so the add-provider draft
agrees with its own editor about an existing conventional credential (the
store joins the derived describe in the same batched call, as
ProviderRow.derivedCredential). ModelsSectionProps makes the renderSlot seat
required so a direct render that forgets it fails to compile; the one such
render in provider-form.client.spec regained a real mount and the test
boilerplate collapsed to renderSlot={() => null}. The extension-slots Agent
Note now states the keyed cell's real override rule (same priority throws,
a different priority shadows), and docs/subsystems/slots.md carries the two
new seats in its hierarchy, both languages.