CommandRow: * icon, SRC: label, remove separator, clean margins

- Replace diamond with * for pixel-perfect fold alignment
- Add SRC: label prefix to command row source field
- Remove vertical bar separator from command row
- Clear footer margin text (no more ---)
- Remove + prefix from offset margin (0x instead of +0x)
- Remove codicon font infrastructure (use editor font chars)

src/editor.h

@@ -37,6 +37,7 @@ public:
     void cancelInlineEdit();
 
     void applySelectionOverlay(const QSet<uint64_t>& selIds);
+    void setCommandRowText(const QString& line);
     void setEditorFont(const QString& fontName);
     static void setGlobalFontName(const QString& fontName);
 
@@ -98,6 +99,10 @@ private:
     };
     InlineEditState m_editState;
 
+    // ── Reentrancy guards ──
+    bool m_clampingSelection = false;
+    bool m_updatingComment = false;
+
     void setupScintilla();
     void setupLexer();
     void setupMargins();
@@ -116,6 +121,7 @@ private:
     bool handleNormalKey(QKeyEvent* ke);
     bool handleEditKey(QKeyEvent* ke);
     void showTypeAutocomplete();
+    void showSourcePicker();
     void showTypeListFiltered(const QString& filter);
     void updateTypeListFilter();
     void paintEditableSpans(int line);