fix: keep the trailing "#" in headings like "# C#"

CheatSheetTests/Sources/DisplayLineTests.swift

@@ -10,6 +10,22 @@ struct DisplayLineTests {
         #expect(parsed.isComplete == false)
     }
 
+    @Test func headingKeepsTrailingHashInLanguageNames() {
+        // Regression: trimmingCharacters(in:) trimmed both ends, so "# C#"
+        // rendered as "C" in both the editor and the widget.
+        #expect("# C#".parsedChecklistLine.text == "C#")
+        #expect("# F#".parsedChecklistLine.text == "F#")
+        #expect("# C# vs F#".parsedChecklistLine.text == "C# vs F#")
+    }
+
+    @Test func headingStripsOnlyLeadingHashes() {
+        let parsed = "## Objective-C".parsedChecklistLine
+
+        #expect(parsed.text == "Objective-C")
+        #expect(parsed.isHeading)
+        #expect(parsed.isTask == false)
+    }
+
     @Test func parsesCompleteTaskLine() {
         let parsed = "- [x] Run build".parsedChecklistLine
 

Shared/Sources/DisplayLine.swift

@@ -57,7 +57,10 @@ public extension String {
 
         if line.hasPrefix("#") {
             isHeading = true
-            line = line.trimmingCharacters(in: CharacterSet(charactersIn: "# "))
+            // Strip only the LEADING hashes. trimmingCharacters(in:) works on both
+            // ends, which silently ate the trailing "#" of headings like "# C#"
+            // and "# F#" -- on a developer cheat sheet those are content.
+            line = String(line.drop(while: { $0 == "#" })).trimmingCharacters(in: .whitespaces)
         }
 
         let markers = ["- [x] ", "* [x] ", "[x] ", "- [X] ", "* [X] ", "[X] "]