Three faults in four lines of the odt metadata.

meta:creation-date and dc:date were taken from generated_time, the run's
own clock, so two runs over unchanged markup produced different odt
bytes. They now carry the document's own instant, so an odt is a
function of its source. That was the last clock stamp in any writer:
every output format is now reproducible.

generated_time is a human-readable run stamp, of the form
"2026-9-17 [38/3] 18:39:35", with unpadded numbers and an iso week in
brackets. It is not a valid xsd:dateTime, which is what ODF asks for in
both of those fields, so what was written there was malformed as well as
unstable.

dc:language now carries the document's own language tag.

The instant is doc_matters.modified_utc, moved there from epub3.d
in this commit: epub3 needs the same value for its dcterms:modified,
and one definition cannot drift from the other. generated_time now
has no caller and is left in place.

(assisted by Claude-Code)

namespace names are identifiers, not addresses, fixes
A namespace URI is an opaque identifier.
  www.w3.org        xhtml, xlink, MathML, rdf-syntax-ns,
                    xml-events, XMLSchema, XMLSchema-instance,
                    xforms, css3-text, data-view, and the xhtml1
                    strict DTD system identifier
  purl.org          dc/elements/1.1, dc/terms
  openoffice.org    office, writer, calc, table, report
  docs.oasis-open   the ODF meta pkg and odf class identifiers

(assisted by Claude-Code)

Modules and imports rewritten to sisudoc.ocda.* and
sisudoc.outputs.*; dub.json excludedSourceFiles and the
spine:abstraction sub-package sourcePaths collapsed to
./src/sisudoc/ocda.

Verified: nix build .#spine-overlay-ldc clean.

(assisted by Claude-Code)

- odd hilighting issue ... must result from my org config, but "fix"
  makes things easier for me.