Plain {} placeholders consume arguments sequentially as before; {N}
refers to the Nth argument (1-based) and may be used to repeat and/or
reorder arguments, e.g. format("{1}/{2}/{1}_{3}.ext", $p1, $p2, $p3).
Mixing is allowed: the {} sequence counter is independent of positional
placeholders (as in Rust format!). Out-of-range indices interpolate the
empty string, consistent with existing too-few-arguments behavior; {0}
is an error value since indices are 1-based.
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
* DSL functions for 64-bit nano-epoch timestamps
* strfntime
* nsec2gmt; move sec/nsec pairs adjacent to one another
* update on-line help
* artifacts from `make dev`
* unit-test files
* New format DSL function
* Updated affected test cases involving on-line help on "for" prefix
* doc-build artifacts for previous commit
* regression-test cases
