A .csv already previewed — as raw text in a <pre>, columns lining up only
if the file happened to be padded. It now renders as an HTML table with the
first row as a header.
The parser is a new pure lib/csv.ts (~50 lines of RFC 4180: quoted
delimiters, "" as a literal quote, newlines inside quotes), so no
papaparse. It never throws: null means "not a table" — an unterminated
quote, or a file with no delimiter at all — and the caller falls back to
the very <pre> it renders today. That fallback is structural rather than a
second code path, because TextView gained a `delim` prop instead of a new
component: it also keeps the ["text", fileURL] query key a restore
invalidates and the retry:false a pinned ?v= version needs.
.tsv is new here — it used to fall through to SniffView and render as
text. The delimiter comes from the extension, never from sniffing.
Big files are capped at 5,000 rows with the count stated on screen
(virtualization is out of scope). Wide files scroll inside .csvbox, whose
rules are scoped under that class on purpose: the file pane carries
.markdown, and the plain .markdown table rules — including the ≤900px one
that turns a table into its own scroller — would otherwise out-specify a
bare .csvview and give the page two nested scrollers.
Not doing: sorting, filtering, search, editing, XLSX.
