feat(text): markdown formatting with floating format bar

lib/const/placed_media_geometry.dart

@@ -27,9 +27,8 @@ abstract final class PlacedMediaGeometry {
     final fontSizeInPixels =
         textFontSizeInWorld(text) * _referencePixelsPerWorldUnit;
 
-    // The text field sits after the 6 px tag, 2 px gap, and the card's 5 px
-    // horizontal padding on each side. Material's borderless field contributes
-    // its intrinsic vertical chrome and retains a 48 px minimum height.
+    // This describes the pre-Markdown TextField card shipped before canonical
+    // coordinates, including its intrinsic vertical chrome and 48 px minimum.
     final painter = TextPainter(
       text: TextSpan(
         text: text.text.isEmpty ? 'Write here...' : text.text,

lib/widgets/draggable_widgets/text/formatted_text_view.dart

@@ -0,0 +1,88 @@
+import 'package:flutter/material.dart';
+import 'package:icarus/widgets/draggable_widgets/text/text_markup.dart';
+
+class FormattedTextView extends StatelessWidget {
+  const FormattedTextView({
+    super.key,
+    required this.text,
+    required this.style,
+    required this.hintText,
+  });
+
+  final String text;
+  final TextStyle style;
+  final String hintText;
+
+  @override
+  Widget build(BuildContext context) {
+    if (text.isEmpty) {
+      return Text(
+        hintText,
+        style: style.copyWith(color: Colors.grey),
+      );
+    }
+    final fontSize = style.fontSize ?? 14;
+    final lines = parseMarkup(text);
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      mainAxisSize: MainAxisSize.min,
+      children: [
+        for (final line in lines) _buildLine(line, fontSize),
+      ],
+    );
+  }
+
+  Widget _buildLine(MarkupLine line, double fontSize) {
+    if (line.plainText.isEmpty) {
+      return SizedBox(
+        height: fontSize * (style.height ?? 1.2),
+      );
+    }
+    final contentStyle = line.kind == MarkupLineKind.heading
+        ? style.copyWith(
+            fontWeight: FontWeight.w600,
+            fontSize: fontSize * markupHeadingScale,
+          )
+        : style;
+    final content = Text.rich(
+      TextSpan(
+        style: contentStyle,
+        children: [
+          for (final inline in line.inlines)
+            if (!inline.isMarker)
+              TextSpan(
+                text: inline.raw,
+                style: contentStyle.copyWith(
+                  fontWeight:
+                      inline.bold ? FontWeight.w700 : contentStyle.fontWeight,
+                  fontStyle:
+                      inline.italic ? FontStyle.italic : contentStyle.fontStyle,
+                ),
+              ),
+        ],
+      ),
+    );
+    if (line.kind == MarkupLineKind.paragraph ||
+        line.kind == MarkupLineKind.heading) {
+      return content;
+    }
+    final glyph =
+        line.kind == MarkupLineKind.bullet ? '•' : '${line.number ?? 1}.';
+    final glyphWidth = fontSize * 1.6;
+    return Row(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        SizedBox(
+          width: glyphWidth,
+          child: Text(
+            glyph,
+            textAlign: TextAlign.right,
+            style: style,
+          ),
+        ),
+        SizedBox(width: fontSize * 0.4),
+        Expanded(child: content),
+      ],
+    );
+  }
+}

lib/widgets/draggable_widgets/text/markup_text_editing_controller.dart

@@ -0,0 +1,45 @@
+import 'package:flutter/material.dart';
+import 'package:icarus/const/settings.dart';
+import 'package:icarus/widgets/draggable_widgets/text/text_markup.dart';
+
+class MarkupTextEditingController extends TextEditingController {
+  MarkupTextEditingController({super.text});
+
+  @override
+  TextSpan buildTextSpan({
+    required BuildContext context,
+    TextStyle? style,
+    required bool withComposing,
+  }) {
+    final baseStyle = style ?? DefaultTextStyle.of(context).style;
+    final mutedStyle = baseStyle.copyWith(
+      color: Settings.tacticalVioletTheme.mutedForeground,
+    );
+    final children = <InlineSpan>[];
+    final lines = parseMarkup(text);
+    for (var index = 0; index < lines.length; index++) {
+      final line = lines[index];
+      if (line.prefix.isNotEmpty) {
+        children.add(TextSpan(text: line.prefix, style: mutedStyle));
+      }
+      final headingStyle = line.kind == MarkupLineKind.heading
+          ? baseStyle.copyWith(
+              fontWeight: FontWeight.w600,
+              fontSize: (baseStyle.fontSize ?? 14) * markupHeadingScale,
+            )
+          : baseStyle;
+      for (final inline in line.inlines) {
+        final inlineStyle = headingStyle.copyWith(
+          color: inline.isMarker
+              ? Settings.tacticalVioletTheme.mutedForeground
+              : headingStyle.color,
+          fontWeight: inline.bold ? FontWeight.w700 : headingStyle.fontWeight,
+          fontStyle: inline.italic ? FontStyle.italic : headingStyle.fontStyle,
+        );
+        children.add(TextSpan(text: inline.raw, style: inlineStyle));
+      }
+      if (index != lines.length - 1) children.add(const TextSpan(text: '\n'));
+    }
+    return TextSpan(style: baseStyle, children: children);
+  }
+}

lib/widgets/draggable_widgets/text/text_format_bar.dart

@@ -0,0 +1,131 @@
+import 'package:flutter/material.dart';
+import 'package:icarus/const/settings.dart';
+import 'package:icarus/widgets/editor_toolbar.dart';
+import 'package:icarus/widgets/draggable_widgets/text/text_markup.dart';
+import 'package:lucide_icons_flutter/lucide_icons.dart';
+import 'package:shadcn_ui/shadcn_ui.dart';
+
+class ToggleBoldIntent extends Intent {
+  const ToggleBoldIntent();
+}
+
+class ToggleItalicIntent extends Intent {
+  const ToggleItalicIntent();
+}
+
+class TextFormatBar extends StatelessWidget {
+  const TextFormatBar({
+    super.key,
+    required this.controller,
+    required this.onApply,
+    required this.tapRegionGroupId,
+  });
+
+  static const double _buttonSize = 28;
+  static const double _padding = 3;
+
+  static const double _gap = 2;
+
+  // Five evenly spaced buttons inside the padding and the 1px border. The
+  // overlay positions the bar from these.
+  static const double width = 5 * _buttonSize + 4 * _gap + 2 * _padding + 2;
+  static const double height = _buttonSize + 2 * _padding + 2;
+
+  final TextEditingController controller;
+  final ValueChanged<TextEditingValue> onApply;
+  final Object tapRegionGroupId;
+
+  @override
+  Widget build(BuildContext context) {
+    return ExcludeFocus(
+      child: TapRegion(
+        groupId: tapRegionGroupId,
+        child: ListenableBuilder(
+          listenable: controller,
+          builder: (context, _) {
+            final value = controller.value;
+            const style =
+                EditorToolbarButtonStyle(size: _buttonSize, iconSize: 16);
+            return Container(
+              width: width,
+              height: height,
+              padding: const EdgeInsets.all(_padding),
+              decoration: BoxDecoration(
+                color: Settings.tacticalVioletTheme.card,
+                // Tighter than the docked toolbar: the bar sits against the
+                // text card's near-square corners.
+                borderRadius: BorderRadius.circular(8),
+                border: Border.all(color: Settings.tacticalVioletTheme.border),
+                boxShadow: const [Settings.floatingMenuShadow],
+              ),
+              child: Row(
+                mainAxisSize: MainAxisSize.min,
+                spacing: _gap,
+                children: [
+                  EditorToolbarButton(
+                    style: style,
+                    showTooltip: false,
+                    tooltip: 'Bold (Ctrl+B)',
+                    active: MarkupEditing.isInlineActive(value, '**'),
+                    onPressed: () => onApply(
+                      MarkupEditing.toggleInline(value, '**'),
+                    ),
+                    icon: const Icon(LucideIcons.bold200),
+                  ),
+                  EditorToolbarButton(
+                    style: style,
+                    showTooltip: false,
+                    tooltip: 'Italic (Ctrl+I)',
+                    active: MarkupEditing.isInlineActive(value, '*'),
+                    onPressed: () => onApply(
+                      MarkupEditing.toggleInline(value, '*'),
+                    ),
+                    icon: const Icon(LucideIcons.italic200),
+                  ),
+                  EditorToolbarButton(
+                    style: style,
+                    showTooltip: false,
+                    tooltip: 'Bullet list',
+                    active: MarkupEditing.lineKindAt(value) ==
+                        MarkupLineKind.bullet,
+                    onPressed: () => onApply(
+                      MarkupEditing.toggleLineKind(
+                          value, MarkupLineKind.bullet),
+                    ),
+                    icon: const Icon(LucideIcons.list200),
+                  ),
+                  EditorToolbarButton(
+                    style: style,
+                    showTooltip: false,
+                    tooltip: 'Numbered list',
+                    active: MarkupEditing.lineKindAt(value) ==
+                        MarkupLineKind.numbered,
+                    onPressed: () => onApply(
+                      MarkupEditing.toggleLineKind(
+                        value,
+                        MarkupLineKind.numbered,
+                      ),
+                    ),
+                    icon: const Icon(LucideIcons.listOrdered200),
+                  ),
+                  EditorToolbarButton(
+                    style: style,
+                    showTooltip: false,
+                    tooltip: 'Heading',
+                    active: MarkupEditing.lineKindAt(value) ==
+                        MarkupLineKind.heading,
+                    onPressed: () => onApply(
+                      MarkupEditing.toggleLineKind(
+                          value, MarkupLineKind.heading),
+                    ),
+                    icon: const Icon(LucideIcons.heading200),
+                  ),
+                ],
+              ),
+            );
+          },
+        ),
+      ),
+    );
+  }
+}