feat(config): configurable generated-section captions (P2)

TOC / links / tags section headings (and their levels) were hardcoded.
Added per-wiki toc_header/toc_header_level, links_header/links_header_level,
tags_header/tags_header_level — defaults Contents / Generated Links /
Generated Tags at level 1, matching upstream (also fixes the tags index
heading: Tags -> Generated Tags).

A caption_line(name, level) helper emits the `=`-markers; the configured
text + level thread through toc_edit / links_edit / tag_links_edit and the
auto_toc save hook. find_section_range matches the configured text, so
regeneration stays idempotent at any level.

Tests: captions_honour_custom_header_and_level (link_health) + config
round-trip + default assertions (index_and_config); existing tag/toc/links
tests updated for the new arity and the Generated Tags default. fmt/clippy
clean (8-arg ops get allow(too_many_arguments), matching the codebase
precedent); 0 Rust test failures; config-parity green.

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

crates/nuwiki-lsp/tests/link_health.rs

@@ -290,7 +290,7 @@ fn build_toc_text_nests_by_level() {
         (2u8, "Sub".into(), "sub".into()),
         (1u8, "Other".into(), "other".into()),
     ];
-    let out = ops::build_toc_text(&items, "Contents");
+    let out = ops::build_toc_text(&items, "Contents", 1);
     assert!(out.starts_with("= Contents =\n"));
     let lines: Vec<&str> = out.lines().collect();
     assert_eq!(lines[0], "= Contents =");
@@ -301,16 +301,30 @@ fn build_toc_text_nests_by_level() {
 
 #[test]
 fn build_toc_text_with_no_headings_is_just_the_heading() {
-    let out = ops::build_toc_text(&[], "Contents");
+    let out = ops::build_toc_text(&[], "Contents", 1);
     assert_eq!(out, "= Contents =\n");
 }
 
+#[test]
+fn captions_honour_custom_header_and_level() {
+    // toc_header="Table of Contents", level 2 → `== Table of Contents ==`.
+    let out = ops::build_toc_text(&[], "Table of Contents", 2);
+    assert_eq!(out, "== Table of Contents ==\n");
+    // links_header at level 3.
+    let pages = vec!["A".to_string(), "B".to_string()];
+    let links = ops::build_links_text(&pages, "All Pages", 3, None);
+    assert!(links.starts_with("=== All Pages ===\n"));
+    // level clamps to 1..=6.
+    assert!(ops::build_toc_text(&[], "X", 9).starts_with("====== X ======"));
+    assert!(ops::build_toc_text(&[], "X", 0).starts_with("= X ="));
+}
+
 // ===== Links text generation =====
 
 #[test]
 fn build_links_text_excludes_current_page() {
     let pages = vec!["A".to_string(), "Home".to_string(), "B".to_string()];
-    let out = ops::build_links_text(&pages, "Generated Links", Some("Home"));
+    let out = ops::build_links_text(&pages, "Generated Links", 1, Some("Home"));
     let lines: Vec<&str> = out.lines().collect();
     assert_eq!(lines[0], "= Generated Links =");
     assert!(lines.contains(&"- [[A]]"));
@@ -321,7 +335,7 @@ fn build_links_text_excludes_current_page() {
 #[test]
 fn build_links_text_no_excludes_includes_all() {
     let pages = vec!["A".to_string(), "B".to_string()];
-    let out = ops::build_links_text(&pages, "Generated Links", None);
+    let out = ops::build_links_text(&pages, "Generated Links", 1, None);
     assert!(out.contains("[[A]]"));
     assert!(out.contains("[[B]]"));
 }
@@ -359,7 +373,7 @@ fn toc_edit_inserts_at_top_when_no_existing_toc() {
     let src = "= One =\n== Two ==\n";
     let ast = parse(src);
     let uri = Url::parse("file:///tmp/page.wiki").unwrap();
-    let edit = ops::toc_edit(src, &ast, &uri, true).expect("got an edit");
+    let edit = ops::toc_edit(src, &ast, &uri, true, "Contents", 1).expect("got an edit");
     let changes = edit.changes.expect("changes map");
     let edits = &changes[&uri];
     assert_eq!(edits.len(), 1);
@@ -375,7 +389,7 @@ fn toc_edit_replaces_existing_toc() {
     let src = "= Contents =\n- [[#stale|Stale]]\n\n= Real =\n";
     let ast = parse(src);
     let uri = Url::parse("file:///tmp/page.wiki").unwrap();
-    let edit = ops::toc_edit(src, &ast, &uri, true).expect("got an edit");
+    let edit = ops::toc_edit(src, &ast, &uri, true, "Contents", 1).expect("got an edit");
     let changes = edit.changes.expect("changes map");
     let edits = &changes[&uri];
     let te = &edits[0];
@@ -390,7 +404,7 @@ fn toc_edit_returns_none_for_empty_doc() {
     let src = "";
     let ast = parse(src);
     let uri = Url::parse("file:///tmp/empty.wiki").unwrap();
-    assert!(ops::toc_edit(src, &ast, &uri, true).is_none());
+    assert!(ops::toc_edit(src, &ast, &uri, true, "Contents", 1).is_none());
 }
 
 #[test]
@@ -401,14 +415,14 @@ fn toc_rebuild_edit_only_acts_when_toc_already_present() {
     let without = "= One =\n== Two ==\n";
     let ast = parse(without);
     assert!(
-        ops::toc_rebuild_edit(without, &ast, &uri, true).is_none(),
+        ops::toc_rebuild_edit(without, &ast, &uri, true, "Contents", 1).is_none(),
         "auto_toc should not insert a TOC where none existed"
     );
 
     // Existing TOC → rebuild refreshes it.
     let with = "= Contents =\n- [[#stale|Stale]]\n\n= Real =\n";
     let ast = parse(with);
-    let edit = ops::toc_rebuild_edit(with, &ast, &uri, true).expect("rebuild edit");
+    let edit = ops::toc_rebuild_edit(with, &ast, &uri, true, "Contents", 1).expect("rebuild edit");
     let te = &edit.changes.unwrap()[&uri][0];
     assert!(te.new_text.contains("[[#real|Real]]"));
     assert!(!te.new_text.contains("Stale"));
@@ -422,7 +436,8 @@ fn links_edit_inserts_when_section_absent() {
     let ast = parse(src);
     let uri = Url::parse("file:///tmp/page.wiki").unwrap();
     let pages = vec!["A".into(), "B".into(), "Home".into()];
-    let edit = ops::links_edit(src, &ast, &uri, "Home", &pages, true).expect("edit");
+    let edit =
+        ops::links_edit(src, &ast, &uri, "Home", &pages, true, "Generated Links", 1).expect("edit");
     let te = &edit.changes.unwrap()[&uri][0];
     assert!(te.new_text.contains("[[A]]"));
     assert!(te.new_text.contains("[[B]]"));
@@ -435,7 +450,8 @@ fn links_edit_replaces_when_section_present() {
     let ast = parse(src);
     let uri = Url::parse("file:///tmp/page.wiki").unwrap();
     let pages = vec!["Fresh".into()];
-    let edit = ops::links_edit(src, &ast, &uri, "Home", &pages, true).expect("edit");
+    let edit =
+        ops::links_edit(src, &ast, &uri, "Home", &pages, true, "Generated Links", 1).expect("edit");
     let te = &edit.changes.unwrap()[&uri][0];
     assert!(te.new_text.contains("[[Fresh]]"));
     assert!(!te.new_text.contains("Stale"));
@@ -447,7 +463,7 @@ fn links_edit_returns_none_for_empty_page_list() {
     let src = "Hi\n";
     let ast = parse(src);
     let uri = Url::parse("file:///tmp/page.wiki").unwrap();
-    assert!(ops::links_edit(src, &ast, &uri, "Home", &[], true).is_none());
+    assert!(ops::links_edit(src, &ast, &uri, "Home", &[], true, "Generated Links", 1).is_none());
 }
 
 // ===== find_orphans =====