fix: use line-ending backslash instead of newline for TOML closing delimiters

Address PR review feedback:
- Replace sep=newline with TOML line-ending backslash so the parsed
  value does not gain a trailing newline when body ends with a quote.
- For literal string (''') fallback, skip to escaped basic string when
  value ends with single quote instead of inserting a newline.
- Make test body multiline so it exercises the """ rendering path,
  and assert no trailing newline in parsed value.

Author: mnriem

src/specify_cli/integrations/base.py

@@ -597,11 +597,11 @@ def _render_toml_string(value: str) -> str:
 
         escaped = value.replace("\\", "\\\\")
         if '"""' not in escaped:
-            sep = "\n" if escaped.endswith('"') else ""
-            return '"""\n' + escaped + sep + '"""'
-        if "'''" not in value:
-            sep = "\n" if value.endswith("'") else ""
-            return "'''\n" + value + sep + "'''"
+            if escaped.endswith('"'):
+                return '"""\n' + escaped + '\\\n"""'
+            return '"""\n' + escaped + '"""'
+        if "'''" not in value and not value.endswith("'"):
+            return "'''\n" + value + "'''"
 
         return '"' + (
             value.replace("\\", "\\\\")

tests/integrations/test_integration_base_toml.py

@@ -205,7 +205,7 @@ def test_toml_prompt_excludes_frontmatter(self, tmp_path, monkeypatch):
         assert "---" not in parsed["prompt"]
 
     def test_toml_no_ambiguous_closing_quotes(self, tmp_path, monkeypatch):
-        """Body ending with `"` must not produce `""""` (#2113)."""
+        """Multiline body ending with `"` must not produce `""""` (#2113)."""
         i = get_integration(self.KEY)
         template = tmp_path / "sample.md"
         template.write_text(
@@ -214,7 +214,8 @@ def test_toml_no_ambiguous_closing_quotes(self, tmp_path, monkeypatch):
             "scripts:\n"
             "  sh: echo ok\n"
             "---\n"
-            'Is "X clearly specified?"\n',
+            "Check the following:\n"
+            '- Correct: "Is X clearly specified?"\n',
             encoding="utf-8",
         )
         monkeypatch.setattr(i, "list_command_templates", lambda: [template])
@@ -226,8 +227,10 @@ def test_toml_no_ambiguous_closing_quotes(self, tmp_path, monkeypatch):
 
         raw = cmd_files[0].read_text(encoding="utf-8")
         assert '""""' not in raw, "closing delimiter must not merge with body quote"
+        assert '"""\n' in raw, "body must use multiline basic string"
         parsed = tomllib.loads(raw)
         assert parsed["prompt"].endswith('specified?"')
+        assert not parsed["prompt"].endswith("\n"), "parsed value must not gain a trailing newline"
 
     def test_toml_closing_delimiter_inline_when_safe(self, tmp_path, monkeypatch):
         """Body NOT ending with `"` keeps closing `\"\"\"` inline (no extra newline)."""