fix(libreoffice): use separate input/output filters and add Calc category

LibreOffice Writer has no CSV export filter.  The shared filter map used
Text for csv in both directions, which made any Writer-category conversion
to csv fail with:

  no export filter for <file>.csv found, aborting.

Root cause: getFilters() looked up the same filters map for the infilter and
the outfilter.  Text is a valid *input* filter for reading delimiter-
separated files in Writer but is not accepted as an *output* filter for the
.csv extension.

Fix:
- Split into separate inputFilters / outputFilters maps so csv can remain
  readable by the text (Writer) category without offering it as a write
  target there.
- Remove csv from properties.to.text so the UI/router no longer exposes
  the unsupported Writer → CSV path.
- Populate the previously-empty filters.calc with correct LibreOffice Calc
  filter names and add spreadsheet formats to properties.from.calc /
  properties.to.calc, enabling conversions such as xlsx → csv, csv → xlsx,
  ods → xlsx, etc. via the Calc module.

Fixes #561

Signed-off-by: Radhakrishnan Pachyappan <gingeekrishna@gmail.com>

tests/converters/libreoffice.test.ts

@@ -166,3 +166,59 @@ test("logs stderr on exec error as well", async () => {
   // The callback still provided stderr; your implementation logs it before settling
   expect(errors).toContain("stderr: EPIPE");
 });
+
+// --- calc (spreadsheet) category --------------------------------------------
+test("uses Calc infilter and outfilter for xlsx -> csv (regression for issue #561)", async () => {
+  await convert("in.xlsx", "xlsx", "csv", "out/out.csv", undefined, mockExecFile);
+
+  const { args } = requireDefined(calls[0], "Expected at least one execFile call");
+  expect(args).toEqual([
+    "--headless",
+    "--infilter=Calc MS Excel 2007 XML",
+    "--convert-to",
+    "csv:Text - txt - csv (StarCalc)",
+    "--outdir",
+    "out",
+    "in.xlsx",
+  ]);
+});
+
+test("uses Calc infilter and outfilter for csv -> xlsx", async () => {
+  await convert("in.csv", "csv", "xlsx", "out/out.xlsx", undefined, mockExecFile);
+
+  const { args } = requireDefined(calls[0], "Expected at least one execFile call");
+  expect(args).toEqual([
+    "--headless",
+    "--infilter=Text - txt - csv (StarCalc)",
+    "--convert-to",
+    "xlsx:Calc MS Excel 2007 XML",
+    "--outdir",
+    "out",
+    "in.csv",
+  ]);
+});
+
+test("uses Calc infilter and outfilter for ods -> xlsx", async () => {
+  await convert("in.ods", "ods", "xlsx", "out/out.xlsx", undefined, mockExecFile);
+
+  const { args } = requireDefined(calls[0], "Expected at least one execFile call");
+  expect(args).toEqual([
+    "--headless",
+    "--infilter=calc8",
+    "--convert-to",
+    "xlsx:Calc MS Excel 2007 XML",
+    "--outdir",
+    "out",
+    "in.ods",
+  ]);
+});
+
+test("pdf -> csv produces no filters (cross-category: not supported via LibreOffice Writer)", async () => {
+  await convert("in.pdf", "pdf", "csv", "out/out.csv", undefined, mockExecFile);
+
+  const { args } = requireDefined(calls[0], "Expected at least one execFile call");
+  // pdf is Writer-category; csv output requires Calc — no valid cross-category
+  // filter exists, so soffice is invoked without explicit filters and will fail
+  // gracefully.  The properties list no longer exposes this combination.
+  expect(args).toEqual(["--headless", "--convert-to", "csv", "--outdir", "out", "in.pdf"]);
+});