feat(config): on-save autoregen family — links/tags/diary-index (P2)

Added per-wiki auto_generate_links, auto_generate_tags, auto_diary_index
(default false, like upstream), wired into the did_save hook mirroring
auto_toc:

- auto_generate_links / auto_generate_tags rebuild the Generated Links /
  Generated Tags section ONLY when it already exists (new
  links_rebuild_edit / tag_links_rebuild_edit, like toc_rebuild_edit) — never
  inserts one into a page that lacks it.
- auto_diary_index regenerates the diary index page when a dated diary entry
  (not the index itself) is saved, via diary_generate_index_edit (handles the
  index file open / on-disk / absent).

auto_tags is recorded as an intentional divergence: nuwiki re-indexes tags on
every change, so the tag metadata is always fresh (no on-disk file to update).

Tests: links_rebuild_edit_only_acts_when_section_present,
tag_links_rebuild_edit_only_acts_when_index_present, config round-trip +
defaults. README/doc/lua comment updated. fmt/clippy clean; 0 Rust failures.

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

crates/nuwiki-lsp/src/config.rs

@@ -75,6 +75,15 @@ pub struct WikiConfig {
     pub links_space_char: String,
     /// Rebuild the page's TOC on save when set.
     pub auto_toc: bool,
+    /// On save, regenerate an existing `Generated Links` section
+    /// (vimwiki's `auto_generate_links`).
+    pub auto_generate_links: bool,
+    /// On save, regenerate an existing `Generated Tags` index section
+    /// (vimwiki's `auto_generate_tags`).
+    pub auto_generate_tags: bool,
+    /// On save of a diary entry, regenerate the diary index page
+    /// (vimwiki's `auto_diary_index`).
+    pub auto_diary_index: bool,
     /// Heading text + level for the generated `:VimwikiTOC` section
     /// (vimwiki's `toc_header` / `toc_header_level`).
     pub toc_header: String,
@@ -208,6 +217,9 @@ impl WikiConfig {
             list_margin: d.list_margin,
             links_space_char: d.links_space_char,
             auto_toc: d.auto_toc,
+            auto_generate_links: d.auto_generate_links,
+            auto_generate_tags: d.auto_generate_tags,
+            auto_diary_index: d.auto_diary_index,
             toc_header: d.toc_header,
             toc_header_level: d.toc_header_level,
             links_header: d.links_header,
@@ -244,6 +256,9 @@ impl WikiConfig {
             list_margin: d.list_margin,
             links_space_char: d.links_space_char,
             auto_toc: d.auto_toc,
+            auto_generate_links: d.auto_generate_links,
+            auto_generate_tags: d.auto_generate_tags,
+            auto_diary_index: d.auto_diary_index,
             toc_header: d.toc_header,
             toc_header_level: d.toc_header_level,
             links_header: d.links_header,
@@ -384,6 +399,9 @@ fn wiki_defaults() -> WikiDefaults {
         list_margin: -1,
         links_space_char: default_links_space_char(),
         auto_toc: false,
+        auto_generate_links: false,
+        auto_generate_tags: false,
+        auto_diary_index: false,
         toc_header: default_toc_header(),
         toc_header_level: 1,
         links_header: default_links_header(),
@@ -409,6 +427,9 @@ struct WikiDefaults {
     list_margin: i32,
     links_space_char: String,
     auto_toc: bool,
+    auto_generate_links: bool,
+    auto_generate_tags: bool,
+    auto_diary_index: bool,
     toc_header: String,
     toc_header_level: u8,
     links_header: String,
@@ -641,6 +662,12 @@ struct RawWiki {
     links_space_char: Option<String>,
     #[serde(default, deserialize_with = "opt_bool_or_int::deserialize")]
     auto_toc: Option<bool>,
+    #[serde(default, deserialize_with = "opt_bool_or_int::deserialize")]
+    auto_generate_links: Option<bool>,
+    #[serde(default, deserialize_with = "opt_bool_or_int::deserialize")]
+    auto_generate_tags: Option<bool>,
+    #[serde(default, deserialize_with = "opt_bool_or_int::deserialize")]
+    auto_diary_index: Option<bool>,
     #[serde(default)]
     toc_header: Option<String>,
     #[serde(default)]
@@ -714,6 +741,9 @@ impl From<RawWiki> for WikiConfig {
             list_margin: r.list_margin.unwrap_or(d.list_margin),
             links_space_char: r.links_space_char.unwrap_or(d.links_space_char),
             auto_toc: r.auto_toc.unwrap_or(d.auto_toc),
+            auto_generate_links: r.auto_generate_links.unwrap_or(d.auto_generate_links),
+            auto_generate_tags: r.auto_generate_tags.unwrap_or(d.auto_generate_tags),
+            auto_diary_index: r.auto_diary_index.unwrap_or(d.auto_diary_index),
             toc_header: r.toc_header.unwrap_or(d.toc_header),
             toc_header_level: r.toc_header_level.unwrap_or(d.toc_header_level),
             links_header: r.links_header.unwrap_or(d.links_header),