feat(render): list_ignore_newline / text_ignore_newline = false → <br>

Implements the deferred half of these options: a soft line break inside a
paragraph / list item can render as <br /> instead of a space.

- Parser: soft breaks now emit a dedicated InlineNode::SoftBreak node
  (parse_inline_seq K::Newline + the list-continuation synthetic join) instead
  of collapsing to Text(" "). Added SoftBreakNode + the variant.
- All inline consumers treat SoftBreak as whitespace: AST visitor (no-op),
  text extraction (index.rs + lib.rs → space), nav/semantic_tokens span_of_inline,
  semantic emit (skip like Text), parser span_of_inline.
- Renderer: render_inlines_break renders top-level SoftBreaks as the
  context-specific string; render_paragraph uses text_ignore_newline,
  render_list_item uses list_ignore_newline; default render_inline → space.
  with_newline_handling builder; export.rs wires both from HtmlConfig.

Default (true/true = upstream default) behaviour is unchanged (space). Updated
3 core tests + 1 parser test that asserted the old Text(" ") shape to treat
SoftBreak as whitespace. New test render_page_html_ignore_newline_controls_soft_breaks.

Gap doc: P3 Config item closed — only the deferred markdown cluster remains.
Full rust suite + clippy clean; Neovim 307, Vim 301/18/21.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/nuwiki-lsp/src/export.rs

@@ -261,6 +261,7 @@ pub fn render_page_html(
         r = r.with_valid_html_tags(cfg.valid_html_tags.clone());
     }
     r = r.with_emoji(cfg.emoji_enable);
+    r = r.with_newline_handling(cfg.text_ignore_newline, cfg.list_ignore_newline);
     r.render_to_string(doc)
 }
 

crates/nuwiki-lsp/src/index.rs

@@ -533,6 +533,7 @@ fn inline_to_text_into(inlines: &[InlineNode], out: &mut String) {
             InlineNode::Keyword(_) => {}
             InlineNode::Transclusion(t) => out.push_str(t.alt.as_deref().unwrap_or(&t.url)),
             InlineNode::RawUrl(r) => out.push_str(&r.url),
+            InlineNode::SoftBreak(_) => out.push(' '),
         }
     }
 }

crates/nuwiki-lsp/src/lib.rs

@@ -1464,6 +1464,7 @@ fn inline_to_text_into(inlines: &[InlineNode], out: &mut String) {
             },
             InlineNode::Transclusion(t) => out.push_str(t.alt.as_deref().unwrap_or(&t.url)),
             InlineNode::RawUrl(r) => out.push_str(&r.url),
+            InlineNode::SoftBreak(_) => out.push(' '),
         }
     }
 }

crates/nuwiki-lsp/src/nav.rs

@@ -145,5 +145,6 @@ pub fn span_of_inline(node: &InlineNode) -> Span {
         InlineNode::ExternalLink(n) => n.span,
         InlineNode::Transclusion(n) => n.span,
         InlineNode::RawUrl(n) => n.span,
+        InlineNode::SoftBreak(n) => n.span,
     }
 }

crates/nuwiki-lsp/src/semantic_tokens.rs

@@ -231,7 +231,7 @@ fn emit_list_item(item: &ListItemNode, text: &str, idx: &LineIndex, out: &mut Ve
 fn emit_inlines(inlines: &[InlineNode], text: &str, idx: &LineIndex, out: &mut Vec<RawToken>) {
     for n in inlines {
         let (kind, span) = match n {
-            InlineNode::Text(_) => continue,
+            InlineNode::Text(_) | InlineNode::SoftBreak(_) => continue,
             InlineNode::Bold(b) => (TOKEN_BOLD, b.span),
             InlineNode::Italic(i) => (TOKEN_ITALIC, i.span),
             InlineNode::BoldItalic(bi) => (TOKEN_BOLD_ITALIC, bi.span),
@@ -268,6 +268,7 @@ fn span_of_inline(node: &InlineNode) -> Span {
         InlineNode::ExternalLink(n) => n.span,
         InlineNode::Transclusion(n) => n.span,
         InlineNode::RawUrl(n) => n.span,
+        InlineNode::SoftBreak(n) => n.span,
     }
 }