build-number

Point Fluent parse errors at the actual mistake fluent-syntax reports where it gave up — the top of the entry it had to discard — not where the mistake is, so every error in errors-se.ftl came out as `662:1: Expected one of "a-zA-Z, Unicode letters, hyphen, or underscore"` with a caret under the indentation. Look inside the discarded slice for what actually breaks these files: a placeable that isn't one (`{€1}` where `{$1}` was meant), an attribute missing its `=`, a line indented with a tab. Report the whole file as one block, each error with its own line, a caret under the span, and what to do about it; fall back to the parser's own wording when nothing is recognised.