Ports the next slice of FileBot's ExpressionFormatMethods.java as Rhai-callable
methods usable inside any { } naming-scheme expression, alongside the existing
any/all_of/concat helpers:
- pad/pad_with: left-pad a value's string form (default '0'), non-mutating,
non-truncating - deliberately a different Rhai method name for the 3-arg
custom-char form (pad_with) since Rhai's own built-in pad(length, char)
right-pads and mutates in place, which collides in behavior (not API) with
what FileBot's zero-padded season/episode numbers need.
- sort_name/sort_initial: move a leading The/A/An article to the end for
alphabetical sorting, e.g. "The Office" -> "Office, The".
- upper_initial/lower_initial: case-convert only the first character.
- acronym: first letter of each word, uppercased.
- validate_file_name: strip characters illegal in filenames, collapse
whitespace runs, trim trailing dots.
- space/space_with, colon/colon_with: separator and colon normalization.
16 new unit tests in functions.rs (143 lib tests total, up from 126) plus 3
new integration tests in expression_format.rs demonstrating the helpers used
inside real naming-scheme expressions (14 total, up from 11). Verified via
cargo test --workspace, cargo check --workspace, and npm run build, all
clean. Updated README (status paragraph and porting-roadmap item 2).
Renamr Scaffold
23c9ca609f