feat: introduce a 'code' mode to display source code lines, add new font assets, and include dedicated tests for code fetching.

engine/fetch_code.py

@@ -0,0 +1,67 @@
+"""
+Source code feed — reads engine/*.py and emits non-blank, non-comment lines
+as scroll items. Used by --code mode.
+Depends on: nothing (stdlib only).
+"""
+
+import ast
+from pathlib import Path
+
+_ENGINE_DIR = Path(__file__).resolve().parent
+
+
+def _scope_map(source: str) -> dict[int, str]:
+    """Return {line_number: scope_label} for every line in source.
+
+    Nodes are sorted by range size descending so inner scopes overwrite
+    outer ones, guaranteeing the narrowest enclosing scope wins.
+    """
+    try:
+        tree = ast.parse(source)
+    except SyntaxError:
+        return {}
+
+    nodes = []
+    for node in ast.walk(tree):
+        if isinstance(node, (ast.FunctionDef, ast.AsyncFunctionDef, ast.ClassDef)):
+            end = getattr(node, "end_lineno", node.lineno)
+            span = end - node.lineno
+            nodes.append((span, node))
+
+    # Largest range first → inner scopes overwrite on second pass
+    nodes.sort(key=lambda x: x[0], reverse=True)
+
+    scope = {}
+    for _, node in nodes:
+        end = getattr(node, "end_lineno", node.lineno)
+        if isinstance(node, ast.ClassDef):
+            label = node.name
+        else:
+            label = f"{node.name}()"
+        for ln in range(node.lineno, end + 1):
+            scope[ln] = label
+
+    return scope
+
+
+def fetch_code():
+    """Read engine/*.py and return (items, line_count, 0).
+
+    Each item is (text, src, ts) where:
+      text  = the code line (rstripped, indentation preserved)
+      src   = enclosing function/class name, e.g. 'stream()' or '<module>'
+      ts    = dotted module path, e.g. 'engine.scroll'
+    """
+    items = []
+    for path in sorted(_ENGINE_DIR.glob("*.py")):
+        module = f"engine.{path.stem}"
+        source = path.read_text(encoding="utf-8")
+        scope = _scope_map(source)
+        for lineno, raw in enumerate(source.splitlines(), start=1):
+            stripped = raw.strip()
+            if not stripped or stripped.startswith("#"):
+                continue
+            label = scope.get(lineno, "<module>")
+            items.append((raw.rstrip(), label, module))
+
+    return items, len(items), 0