Adds src/lib/agent/attachments.ts (parseAttachment/previewForModel/
summarise for xlsx, xls, csv, pdf — text-layer or scanned, via
pdftotext — image and plain text) with fixtures under
src/lib/agent/__fixtures__/, POST /api/chat/attachments (multipart
upload into an append-only ask_messages row, rasterising a scanned
PDF's first pages so they ride along as vision images the same way a
photographed slip does), and the read_attachment / send_to_po_pipeline
tools in tools-actions.ts. send_to_po_pipeline mirrors
/api/purchase-orders/upload's own hash-dedupe-then-create logic
directly against PocketBase rather than a same-process HTTP call (no
reliable base URL to call itself with from a server-side tool handler).
chat-view.tsx gained a second attach control (FileUp icon) alongside
the existing PO-upload paperclip, wired to the new route; pending
attachment chips ride along on the next message the same way pending
photos already do.
Deviation: send_to_po_pipeline takes { id, site } (the plan's { id }
alone can't resolve which site's purchase_orders row to create,
since /api/purchase-orders/upload always required one).
Live browser check skipped: ask_messages doesn't exist yet in the
target PocketBase (pending the user's --apply of Task 1's schema).
Covered by mocked unit tests and real fixture files instead.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
