fix(follow-link): two-step <CR> — first wraps, second follows

User feedback: the smart `<CR>` should give the user a chance to
review/edit the freshly-created wikilink before committing to the
follow. Matches upstream vimwiki's flow.

`follow_link_or_create` (Lua + VimL) now:
  1. Cursor already inside `[[…]]` → follow immediately.
  2. Cursor on a bare word → wrap it as `[[word]]`, place cursor
     inside, and STOP. A second `<CR>` then follows.
  3. Neither — fall through to plain definition request so users
     can still chord follow without a target word.

Verified: cursor on `MyPage rest` →
  1st `<CR>` → `[[MyPage]] rest` (buffer unchanged)
  2nd `<CR>` → opens `MyPage.wiki` (the synthesised future page).

381 tests still pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

autoload/nuwiki/commands.vim

@@ -144,16 +144,28 @@ function! s:wrap_cword_as_wikilink() abort
   return 1
 endfunction
 
+" Two-step behaviour matching vimwiki:
+"   1. First press on a bare word → wrap it as `[[word]]` and stop.
+"   2. Cursor is now inside `[[…]]`; next press follows the link.
+"   3. Press inside an existing `[[…]]` follows immediately.
 function! nuwiki#commands#follow_link_or_create() abort
-  if !s:cursor_inside_wikilink()
-    call s:wrap_cword_as_wikilink()
+  if s:cursor_inside_wikilink()
+    if exists(':LspDefinition') == 2
+      LspDefinition
+    else
+      echohl WarningMsg
+      echom 'nuwiki: :LspDefinition unavailable; install vim-lsp'
+      echohl None
+    endif
+    return
   endif
+  if s:wrap_cword_as_wikilink()
+    " Wrapped — wait for the user's second <CR> to follow.
+    return
+  endif
+  " Nothing to wrap — fall through.
   if exists(':LspDefinition') == 2
     LspDefinition
-  else
-    echohl WarningMsg
-    echom 'nuwiki: :LspDefinition unavailable; install vim-lsp'
-    echohl None
   endif
 endfunction