fix(review): close all 2026-06-03 codebase-review findings (R1-R18)

Resolves the 18 findings from the parallel codebase review, tracked in
development/vimwiki-gap.md.

Correctness / perf:
- Wiki.config -> Arc<WikiConfig> so cloning a Wiki is a refcount bump (R5)
- WorkspaceIndex::remove is no longer O(n^2): a per-source contributions
  map limits the scan to buckets the source actually wrote into (R6)
- render_color now expands color_tag_template (__STYLE__/__CONTENT__),
  consuming the previously-dead field; ColorNode documented as an
  extension point; 3 renderer tests added (R3/R4)
- wiki_root_for returns empty/nil on no-match instead of falling back to
  the first wiki (R2); auto_header honours links_space_char (R7)

Cleanup / dedup:
- Remove dead #[allow(dead_code)] stubs + uncalled pub helpers, narrow
  imports (R10/R11)
- Dedup span_of_inline x3 -> InlineNode::span() (R12)
- diary_step single read lock; page_captions single pass (R13)
- Lua auto_header loop -> wiki_list(); detect_current_symbol cleanup
  (R14/R18)

Client / docs:
- :VimwikiNormalizeLink Vim cmds -> <q-args> (R17); ftplugin header fix
  (R16); vars.vim multi-wiki limitation documented (R15)
- Document 19 config options in README.md + doc/nuwiki.txt; fix
  list_margin/shiftwidth doc and stale comments (R1/R9)
- R8 investigated, confirmed not a real bug (documented)

Verified: Neovim harness 307, Vim harness 301/18/21, Rust suite 568, all
0 failed; clippy clean; fresh parallel-agent audit found no regressions.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

doc/nuwiki.txt

@@ -178,6 +178,23 @@ plugin: >
 `diagnostic.link_severity`        `'warn'`
     Severity of broken-link diagnostics: `off`, `hint`, `warn`, `error`.
 
+                                                          *g:nuwiki_auto_chdir*
+`auto_chdir`       false
+    `:lcd` into the owning wiki's root when a wiki buffer becomes current.
+    Mirrors vimwiki's `auto_chdir`. Vim users set |g:nuwiki_auto_chdir|.
+
+                                                         *g:nuwiki_auto_header*
+`auto_header`      false
+    Insert a level-1 header derived from the filename on new (empty) wiki
+    pages. Honours `links_space_char` (so `My_Page.wiki` → `= My Page =`).
+    Mirrors vimwiki's `auto_header`. Vim users set |g:nuwiki_auto_header|.
+
+                                                         *g:nuwiki_no_calendar*
+`use_calendar`     true
+    When true (default), wire up calendar-vim integration if it is on the
+    runtimepath (`g:calendar_action` / `g:calendar_sign`). Set to false, or
+    define |g:nuwiki_no_calendar| before setup(), to opt out.
+
 Per-wiki options ~
 
 Every option in this list lives on a `wikis[i] = {...}` entry. Defaults
@@ -197,6 +214,22 @@ match upstream vimwiki.
 `diary_caption_level`    `0`
 `diary_sort`             `'desc'` | `'asc'`
 `diary_header`           `'Diary'`
+`diary_months`           English month names — month-number → display name
+                         used in the diary index headings.
+`create_link`            `true` — create the target page when following a link
+                         to a missing page; `false` makes the follow a no-op.
+`dir_link`               `''` — index stem opened when following a link to a
+                         directory (e.g. `'index'`); empty opens the directory.
+`bullet_types`           `['-', '*', '#']` — unordered-bullet glyphs for this
+                         wiki; drives `cycle_bullets`.
+`cycle_bullets`          `false` — rotate an unordered item's glyph through
+                         `bullet_types` as it is indented/dedented.
+`generated_links_caption` `false` — emit `[[page|Heading]]` (first heading as
+                         caption) from `:VimwikiGenerateLinks`.
+`toc_link_format`        `0` — `0` = `[[#anchor|title]]` (with description);
+                         `1` = `[[#anchor]]` (anchor only).
+`table_reduce_last_col`  `false` — don't pad the last table column to fill;
+                         keep it at its minimum width.
 `html_path`              Path for `:Vimwiki2HTML` output.
 `template_path`          Path holding `<name>.tpl` templates.
 `template_default`       `'default'`
@@ -206,6 +239,23 @@ match upstream vimwiki.
 `html_filename_parameterization` `false` — encode subdir paths into the HTML
                          filename instead of nesting directories.
 `color_dic`              `{}` — map of `{ name = 'color' }` for `:NuwikiColorize`.
+`color_tag_template`     `'<span style="__STYLE__">__CONTENT__</span>'` — HTML
+                         emitted for a `color_dic` colour span. `__STYLE__` →
+                         `color:<css>`, `__CONTENT__` → the rendered inner HTML.
+`valid_html_tags`        `'b,i,s,u,sub,sup,kbd,br,hr,div,center,strong,em'` —
+                         comma-separated inline HTML tags passed through export
+                         unescaped (`span` is always allowed for colour spans).
+`emoji_enable`           `true` — substitute `:alias:` emoji shortcodes with
+                         their glyph during HTML export.
+`text_ignore_newline`    `true` — a single newline inside a paragraph renders
+                         as a space in HTML; `false` emits `<br>`.
+`list_ignore_newline`    `true` — a single newline inside a list item renders
+                         as a space in HTML; `false` emits `<br>`.
+`rss_name`               `'rss.xml'` — filename of the generated diary RSS feed,
+                         relative to `html_path`.
+`rss_max_items`          `10` — cap on the number of diary items in the RSS feed.
+`user_htmls`             `{}` — basenames of HTML files with no wiki source that
+                         `:VimwikiAll2HTML` must not prune.
 `custom_wiki2html`       `''` — external converter command. When set, export
                          shells out to it instead of the built-in renderer,
                          called as: <cmd> <force> <syntax> <ext> <out_dir>
@@ -231,8 +281,11 @@ match upstream vimwiki.
 `listsyms`               `' .oOX'` — checkbox progression characters.
 `listsym_rejected`       `'-'` — glyph for a cancelled checkbox `[-]`.
 `listsyms_propagate`     `true`
-`list_margin`            `-1` — spaces before a list bullet; `-1` follows
-                         `shiftwidth`.
+`list_margin`            `-1` — spaces before a generated list bullet (TOC /
+                         generated links). `-1` means "no extra margin": the
+                         server can't read the editor's `shiftwidth`, so it
+                         clamps negative values to `0`. Set a non-negative
+                         number to force a fixed indent.
 `links_space_char`       `' '`
 
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