feat(lsp): wire diary/auto_toc/links_space_char/list_margin; drop client-side keys

Consume several per-wiki config keys that the server deserialized but
ignored, and remove keys whose effect is purely client-side:

- diagnostics: re-publish open-doc diagnostics on
  didChangeConfiguration so a link_severity change takes effect
  immediately; fix the single-key unwrap in apply_change so a minimal
  `{ diagnostic: {...} }` payload isn't mistaken for a namespace wrapper.
- auto_toc: rebuild an existing TOC section on save (new
  ops::toc_rebuild_edit, no-op when the page has no TOC).
- diary index: honour diary_header, diary_sort and diary_caption_level
  when rendering the diary index body.
- links_space_char: apply on rename so spaces in the link target and
  the on-disk path become the configured glyph (default " " = verbatim).
- list_margin: thread the per-wiki value into render_page_html.
- remove nested_syntaxes, maxhi and diary_start_week_day from the server
  config: nested-syntax and heading highlighting are client-side, and
  the weekly diary is ISO-week based so a custom week start has no clean
  server-side meaning.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

crates/nuwiki-lsp/src/lib.rs

@@ -504,8 +504,33 @@ impl LanguageServer for Backend {
         // is out of scope here; for now we just accept the new
         // values so later commands see the right diagnostic settings etc.
         // Multi-wiki support revisits this with proper rebuild semantics.
-        let mut cfg = self.config.write().expect("config lock poisoned");
-        cfg.apply_change(&params.settings);
+        {
+            let mut cfg = self.config.write().expect("config lock poisoned");
+            cfg.apply_change(&params.settings);
+        }
+
+        // A severity change (e.g. diagnostic.link_severity) only affects
+        // already-published diagnostics once we re-run link-health checks for
+        // open docs — otherwise the editor keeps showing the old severity until
+        // the next edit. Refresh every wiki's open docs against the new config.
+        let wiki_ids: Vec<crate::wiki::WikiId> = self
+            .wikis
+            .read()
+            .expect("wikis lock poisoned")
+            .iter()
+            .map(|w| w.id)
+            .collect();
+        for wiki_id in wiki_ids {
+            refresh_open_diagnostics_for_wiki(
+                wiki_id,
+                Arc::clone(&self.documents),
+                Arc::clone(&self.wikis),
+                Arc::clone(&self.config),
+                self.client.clone(),
+                Arc::clone(&self.use_utf8),
+            )
+            .await;
+        }
     }
 
     async fn shutdown(&self) -> LspResult<()> {
@@ -575,15 +600,36 @@ impl LanguageServer for Backend {
     }
 
     async fn did_save(&self, params: DidSaveTextDocumentParams) {
-        // When `auto_export` is set on the resolved wiki, run
-        // the equivalent of `nuwiki.export.currentToHtml` after the file
-        // hits disk. Best-effort — failures are logged but do not bubble
-        // to the client. Skips pages with the `%nohtml` directive.
         let uri = params.text_document.uri.clone();
         let wiki = match self.wiki_for_uri(&uri) {
             Some(w) => w,
             None => return,
         };
+
+        // When `auto_toc` is set, rebuild an existing `= Contents =` section
+        // on save and push the change back to the buffer via
+        // `workspace/applyEdit`. Only rebuilds a TOC that's already there —
+        // it never inserts one into a page that didn't have it.
+        if wiki.config.auto_toc {
+            let edit = {
+                self.documents.get(&uri).and_then(|doc| {
+                    commands::ops::toc_rebuild_edit(
+                        &doc.text,
+                        &doc.ast,
+                        &uri,
+                        self.use_utf8.load(Ordering::Relaxed),
+                    )
+                })
+            };
+            if let Some(edit) = edit {
+                let _ = self.client.apply_edit(edit).await;
+            }
+        }
+
+        // When `auto_export` is set on the resolved wiki, run
+        // the equivalent of `nuwiki.export.currentToHtml` after the file
+        // hits disk. Best-effort — failures are logged but do not bubble
+        // to the client. Skips pages with the `%nohtml` directive.
         if !wiki.config.html.auto_export {
             return;
         }