article mode: inject the page title as # heading, jargon loanword rule

When the render would inject the page title as an h1 (markdown.has_h1 is
False for the body), an article job's text carries the same '# {title}'
line: the title translates in document context and the opening paragraphs
see the heading (works both ways). The heading's pair in the decomposed
result becomes the title fragment — heading text only, pure prose, never
stored as a body chunk; a demoted or merged heading skips the title,
which stays pending for a scoped title job. The job covers the title key
so it is not double-dispatched afterwards.

Prompt: prefer established technical loanwords with English roots over
forced localizations (frontend -> frontti in Finnish, not etupääte).

Verified offline (title extraction, demoted-heading skip, no-injection
path) and live against ollama qwen3.8:27b: the standalone title job gave
'Alkuun pääseminen', the article job then overwrote it with the
in-context 'Aloitus' matching the body's translated heading.

docs/llm-translation.md

@@ -125,7 +125,12 @@ Three job modes, in increasing granularity:
 
 Titles are jobs like any other in all modes (`kind="title"` keeps its
 article-opening context rule; in `markdown` mode a title crosses as
-plain text, since it carries no markup by construction).
+plain text, since it carries no markup by construction). Additionally, an
+`article` job carries the page title injected as a `# {title}` line at
+the top when the render would inject it (the body has no h1 of its own):
+the title translates in document context and the opening paragraphs see
+the heading. The heading's pair in the decomposed result becomes the
+title fragment (heading text only, never stored as a body chunk).
 
 ### Dispatch and validation