feat(claudbg-vcxz): document filter syntax in help modal

Add wildcard, AND/OR logic, and date format to the Filter fields section;
widen the help dialog to 40 cols to accommodate the new entries cleanly.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.beans/claudbg-vcxz--document-filter-syntax-in-help-text.md

@@ -1,10 +1,11 @@
 ---
 # claudbg-vcxz
 title: Document filter syntax in help text
-status: todo
+status: in-progress
 type: task
+priority: normal
 created_at: 2026-04-01T16:47:07Z
-updated_at: 2026-04-01T16:47:07Z
+updated_at: 2026-04-01T17:06:57Z
 ---
 
 Add filter field documentation to the help text shown in the TUI (e.g. '?' help modal). Users should be able to discover available filter fields and operators without reading source code.

src/tui/modals/help_modal.rs

@@ -15,8 +15,8 @@ use crate::tui::state::AppState;
 // ---------------------------------------------------------------------------
 
 /// Dialog dimensions.
-const DIALOG_WIDTH: u16 = 36;
+const DIALOG_WIDTH: u16 = 40;
-const DIALOG_HEIGHT: u16 = 42;
+const DIALOG_HEIGHT: u16 = 48;
 
 /// Compute a centered [`Rect`] of the given size within `area`.
 fn centered_rect(width: u16, height: u16, area: Rect) -> Rect {
@@ -58,11 +58,14 @@ const HELP_TEXT: &str = "\
   project:foo    substring\n\
   id:abc         substring\n\
   agents>0       numeric\n\
-  messages<50    numeric (alias: msgs)\n\
+  messages<50    numeric (msgs=alias)\n\
   in>5000        input tokens\n\
   out<1000       output tokens\n\
   tokens>50000   total tokens\n\
-  date>2026-01   date\n\
+  date>2026-01   date (YYYY-MM)\n\
+  model:*        non-empty (wildcard)\n\
+  Combine:  expr AND expr\n\
+            expr OR  expr\n\
 \n\
  Search (transcript)\n\
   t / /     open search\n\