feat(generate): insert links/tags sections at the cursor line too

Extend the cursor-line insertion from :NuwikiTOC to the other buffer
list generators: :NuwikiGenerateLinks and :NuwikiGenerateTagLinks. They
appended at end-of-file; a fresh section now goes at the cursor line
(with a leading blank), matching :NuwikiTOC. An existing section is still
refreshed in place, and the auto_generate_*-on-save hooks are unaffected
(they only ever replace).

Shared section_insert() helper computes the insert position/block for all
three (cursor line clamped to the document, else the per-command fallback:
top of file for TOC, EOF for links/tags). Clients send the 0-based cursor
line; handlers parse it via parse_uri_line_arg and thread it through
links_edit / tag_links_edit. Rebuild variants pass None.

Tests: links_edit_inserts_at_cursor_line + tag_links_edit_inserts_at_cursor_line.
577 passed, clippy clean, keymap harnesses green. Docs updated.

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

lua/nuwiki/commands.lua

@@ -521,12 +521,12 @@ end
 -- `:VimwikiGenerateLinks [rel_path]` — optional path scopes the links to a
 -- subtree via the server's generateForPath; no arg = every page.
 M.links_generate = function(path)
+  -- Cursor line (0-based) so a fresh section is inserted there.
+  local line = vim.api.nvim_win_get_cursor(0)[1] - 1
   if path and path ~= '' then
-    local args = uri_args()[1]
-    args.path = path
-    exec('nuwiki.links.generateForPath', { args })
+    exec('nuwiki.links.generateForPath', { { uri = buf_uri(), path = path, line = line } })
   else
-    exec('nuwiki.links.generate', uri_args())
+    exec('nuwiki.links.generate', { { uri = buf_uri(), line = line } })
   end
 end
 
@@ -606,7 +606,8 @@ function M.tags_search(query)
 end
 
 function M.tags_generate_links(tag)
-  local args = { uri = buf_uri() }
+  -- Cursor line (0-based) so a fresh section is inserted there.
+  local args = { uri = buf_uri(), line = vim.api.nvim_win_get_cursor(0)[1] - 1 }
   if tag and tag ~= '' then
     args.tag = tag
   end