Insert a working repeat block instead of its description

The placeholder chooser showed repeat blocks as "{{#claims}} … {{/claims}}" and
inserted exactly that on double-click -- the ellipsis is a label, so the saved
template rendered a literal "…" per claim instead of the claim.

Chooser rows are data now: each carries the text it reads as and, separately,
the snippet it inserts. A block contributes a complete, ready-to-edit block with
a sample line built from its own placeholders, and lands on a line of its own
when the cursor sits behind existing text.

Covered from both sides: the snippets are checked against the template validator
and renderer, and a UI test drives the real dialog -- insert, save, send -- and
asserts the mail carries actual claim lines. The Tk tests share one root (the
icon library binds its images to the first one) and skip without a display.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

tests/test_options_dialog_ui.py

@@ -0,0 +1,138 @@
+from email.parser import BytesParser
+from email.policy import default
+
+import pytest
+
+tk = pytest.importorskip("tkinter")
+
+from ccma.config import AppConfig  # noqa: E402
+from ccma.domain.mail_templates import placeholder_entries  # noqa: E402
+from ccma.services.welcome_mail import generate_and_send_welcome_mail  # noqa: E402
+from ccma.storage.repository import MemberRepository  # noqa: E402
+
+
+# One root for the whole session: the icon library binds its images to the first
+# Tk instance, so tearing a root down between tests would invalidate them.
+@pytest.fixture(scope="session")
+def tk_root():
+    from ccma.ui.theme import load_theme
+
+    try:
+        root = tk.Tk()
+    except tk.TclError as exc:  # headless CI has no display to build widgets on
+        pytest.skip(f"kein Display verfügbar: {exc}")
+    root.withdraw()
+    load_theme(root, "dark")
+    yield root
+    root.destroy()
+
+
+@pytest.fixture
+def repository(tmp_path):
+    repository = MemberRepository(tmp_path / "store")
+    repository.initialize()
+    organization = repository.get_configuration()["organization"]
+    organization.update(
+        {
+            "name": "Chaos Computer Club Mannheim e.V.",
+            "email": "verwaltung@example.org",
+            "iban": "DE98670505050038907751",
+            "bic": "MANSDE66XXX",
+        }
+    )
+    repository.save_organization(organization)
+    return repository
+
+
+def _open_options(tk_root, repository):
+    from ccma.ui.options_dialog import OptionsDialog
+
+    dialog = OptionsDialog(tk_root, AppConfig(store_path=str(repository.root)), repository)
+    tk_root.update()
+    return dialog
+
+
+def _block_row(dialog):
+    for row in dialog.mail_template_placeholders.get_children():
+        label = str(dialog.mail_template_placeholders.item(row, "values")[0])
+        if label.startswith("{{#claims}}"):
+            return row
+    raise AssertionError("Der Wiederholungsblock fehlt in der Platzhalterliste.")
+
+
+def test_double_click_on_a_block_is_wired_up(tk_root, repository):
+    dialog = _open_options(tk_root, repository)
+    try:
+        assert dialog.mail_template_placeholders.bind("<Double-1>")
+        assert dialog.mail_template_snippets[_block_row(dialog)] == next(
+            entry.snippet
+            for entry in placeholder_entries("welcome")
+            if entry.label.startswith("{{#claims}}")
+        )
+    finally:
+        dialog.grab_release()
+        dialog.destroy()
+
+
+def test_inserting_a_block_puts_editable_template_code_into_the_body(tk_root, repository):
+    dialog = _open_options(tk_root, repository)
+    try:
+        dialog.mail_template_body.delete("1.0", "end")
+        dialog.mail_template_body.insert("1.0", "Offen sind aktuell:")
+        dialog.mail_template_placeholders.selection_set(_block_row(dialog))
+        dialog._insert_mail_placeholder()
+        tk_root.update()
+        body = dialog.mail_template_body.get("1.0", "end-1c")
+    finally:
+        dialog.grab_release()
+        dialog.destroy()
+
+    assert "…" not in body
+    assert "{{#claims}}" in body and "{{/claims}}" in body
+    assert "{{claim.description}}" in body
+    # The block was appended behind existing text and still starts on its own line.
+    assert body.splitlines()[0] == "Offen sind aktuell:"
+    assert body.splitlines()[1] == "{{#claims}}"
+
+
+def test_edited_template_survives_saving_and_produces_real_lines_in_the_mail(
+    tk_root, repository, tmp_path
+):
+    member = repository.create_member(
+        first_name="Ada", last_name="Lovelace", birth_date="1990-01-01"
+    )
+    member.email = "ada@example.org"
+    member.accepted_at = "2026-08-20"
+    repository.save_member(member)
+    repository.create_manual_claim(
+        member.member_id, title="Aufnahmegebühr", amount="15.00", due_date="2026-09-17"
+    )
+
+    dialog = _open_options(tk_root, repository)
+    try:
+        dialog.mail_template_subject_var.set("Willkommen, {{member.first_name}}")
+        dialog.mail_template_body.delete("1.0", "end")
+        dialog.mail_template_body.insert("1.0", "Offen sind aktuell:\n")
+        dialog.mail_template_placeholders.selection_set(_block_row(dialog))
+        dialog._insert_mail_placeholder()
+        tk_root.update()
+        dialog._save_mail_templates()
+    finally:
+        dialog.grab_release()
+        dialog.destroy()
+
+    generated = generate_and_send_welcome_mail(
+        repository,
+        member.member_id,
+        delivery_mode="local",
+        output_path=tmp_path / "Willkommen.eml",
+        sender_name="Verwaltung C3MA",
+        sender_email="verwaltung@example.org",
+        signature="Der Vorstand",
+    )
+
+    content = BytesParser(policy=default).parsebytes(
+        generated.export_path.read_bytes()
+    ).get_content()
+    assert "Aufnahmegebühr (fällig 17.09.2026): 15.00 Euro" in content
+    assert "…" not in content