Initial import of LogDarioSeq baseline

Establishes version control for the personal Logseq DB fork before
starting the server-client architecture migration and domain features
described in docs/agent-guide and the approved implementation plan.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

cli/lib/display_width.ml

@@ -0,0 +1,56 @@
+let is_combining code =
+  (code >= 0x0300 && code <= 0x036f)
+  || (code >= 0x1ab0 && code <= 0x1aff)
+  || (code >= 0x1dc0 && code <= 0x1dff)
+  || (code >= 0x20d0 && code <= 0x20ff)
+  || (code >= 0xfe20 && code <= 0xfe2f)
+
+let is_wide code =
+  code >= 0x1100
+  && (code <= 0x115f || code = 0x2329 || code = 0x232a
+     || (code >= 0x2e80 && code <= 0xa4cf && code <> 0x303f)
+     || (code >= 0xac00 && code <= 0xd7a3)
+     || (code >= 0xf900 && code <= 0xfaff)
+     || (code >= 0xfe10 && code <= 0xfe19)
+     || (code >= 0xfe30 && code <= 0xfe6f)
+     || (code >= 0xff00 && code <= 0xff60)
+     || (code >= 0xffe0 && code <= 0xffe6))
+
+let char_width code =
+  if code = 0 || code < 32 || (code >= 0x7f && code < 0xa0) then 0
+  else if is_combining code then 0
+  else if is_wide code then 2
+  else 1
+
+external chars_of_string : string -> string array = "from" [@@mel.scope "Array"]
+
+let unicode_chars text =
+  Ustring.(of_string text |> to_string) |> chars_of_string
+
+let code_point ch =
+  match Js.String.codePointAt ~index:0 ch with Some code -> code | None -> 0
+
+let width text =
+  unicode_chars text
+  |> Array.fold_left (fun acc ch -> acc + char_width (code_point ch)) 0
+
+let take text max_width =
+  let rec loop chars index acc_width acc =
+    if index >= Array.length chars then Vec.string_concat "" acc
+    else
+      let ch = chars.(index) in
+      let next_width = acc_width + char_width (code_point ch) in
+      if next_width > max_width then Vec.string_concat "" acc
+      else loop chars (index + 1) next_width (Vec.push_back acc ch)
+  in
+  if max_width <= 0 then "" else loop (unicode_chars text) 0 0 Vec.empty
+
+let ellipsis = Cli_platform.Symbols.ellipsis
+
+let truncate text max_width =
+  let max_width = max 1 max_width in
+  if width text <= max_width then text
+  else
+    let ellipsis_width = width ellipsis in
+    if max_width <= ellipsis_width then take ellipsis max_width
+    else take text (max_width - ellipsis_width) ^ ellipsis