feat: add Gemini and Spartan protocol support

app/test/gemtext_test.dart

@@ -0,0 +1,109 @@
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:mews/mews/document.dart';
+import 'package:mews/mews/gemtext.dart';
+
+const page = '''
+# A capsule
+
+Some opening text.
+A second line of it.
+
+## A section
+
+* one
+* two
+
+=> index.gmi The index
+=> retro.gmi 2026-10-08 Collecting retro phones
+=> first.gmi 2026-09-21 First post
+
+> a quoted line
+> and another
+
+```rust
+fn main() {}
+```
+
+#### four hashes are text
+''';
+
+void main() {
+  test('gemtext converts to the document model', () {
+    final parsed = parseGemtextPage(source: page, url: 'gemini://capsule.example/index.gmi');
+
+    expect(parsed.url, 'gemini://capsule.example/index.gmi');
+    expect(parsed.specVersion, gemtextSpecVersion);
+    expect(parsed.isMews, isTrue);
+    expect(parsed.title, 'A capsule');
+    expect(parsed.direction, TextDirection.ltr);
+
+    final headings = parsed.body
+        .whereType<HeadingBlock>()
+        .map((h) => (h.level, (h.inline.single as MewsText).text))
+        .toList();
+    expect(headings, [
+      (1, 'A capsule'),
+      (2, 'A section'),
+    ]);
+
+    // Each text line is its own paragraph.
+    final paragraphs = parsed.body.whereType<ParagraphBlock>().length;
+    expect(paragraphs, 3); // Two opening lines and the four-hashes line.
+
+    final lists = parsed.body.whereType<ListBlock>().toList();
+    expect(lists, hasLength(2));
+    expect(lists.first.items, hasLength(2));
+    expect(
+        ((lists.first.items.first.blocks.single as ParagraphBlock).inline.single as MewsText).text,
+        'one');
+
+    // Consecutive link lines form one list, so a menu reads as a menu.
+    expect(lists.last.items, hasLength(3));
+
+    final quotes = parsed.body.whereType<QuoteBlock>().toList();
+    expect(quotes, hasLength(1));
+    expect(quotes.first.children, hasLength(2));
+
+    final pre = parsed.body.whereType<PreBlock>().single;
+    expect(pre.text, 'fn main() {}');
+  });
+
+  test('dated links become entries, resolved absolute', () {
+    final parsed = parseGemtextPage(source: page, url: 'gemini://capsule.example/index.gmi');
+
+    expect(
+      parsed.entries.map((e) => (e.url, e.date, e.title)).toList(),
+      [
+        ('gemini://capsule.example/retro.gmi', DateTime(2026, 10, 8), 'Collecting retro phones'),
+        ('gemini://capsule.example/first.gmi', DateTime(2026, 9, 21), 'First post'),
+      ],
+    );
+  });
+
+  test('a link without a label shows its address', () {
+    final parsed = parseGemtextPage(
+        source: '=> gemini://else.example/x.gmi', url: 'gemini://capsule.example/');
+
+    final list = parsed.body.whereType<ListBlock>().single;
+    final link = ((list.items.single.blocks.single as ParagraphBlock).inline.single as MewsLink);
+    expect(link.href, 'gemini://else.example/x.gmi');
+    expect((link.children.single as MewsText).text, 'gemini://else.example/x.gmi');
+  });
+
+  test('an unterminated pre block keeps its lines', () {
+    final parsed = parseGemtextPage(
+        source: '```\nstill inside', url: 'gemini://capsule.example/');
+
+    expect(parsed.body.whereType<PreBlock>().single.text, 'still inside');
+  });
+
+  test('right-to-left text is written in its own direction', () {
+    final parsed = parseGemtextPage(
+        source: '# שלום\nטקסט בעברית', url: 'gemini://capsule.example/he.gmi');
+
+    expect(parsed.direction, TextDirection.rtl);
+    expect(parsed.lang, 'he');
+    expect(parsed.title, 'שלום');
+  });
+}