tools: keep tool output whole and let the request-prep pass cap it

run_argv, run_argv_batch, fetch, fetch_local, and the vcs tools now return
their output whole, so the request-prep cap trims it on the wire and names
its document. A fetched page or a long log reads on from the tool message,
with no re-fetch and no re-run.

The run_argv_batch run budget stays as an execution guard: it stops a
runaway batch from spawning further huge-output steps.

Co-authored-by: CommandCodeBot <noreply@commandcode.ai>

tests/test_tools/test_get_truncated.py

@@ -84,42 +84,6 @@ async def test_get_truncated_file_missing(workspace: Path) -> None:
     assert out.startswith("error:")
 
 
-async def test_get_truncated_serves_a_fetch_body_without_refetching(monkeypatch) -> None:
-    """A fetch body's token reads the stored remainder; the request is not repeated."""
-    from plyngent.tools.net.fetch_local import format_fetch_result
-
-    fetch_module = importlib.import_module("plyngent.tools.net.fetch_local")
-
-    async def _must_not_refetch(*_args: object, **_kwargs: object) -> str:
-        msg = "resuming a fetch body must not re-run the request"
-        raise AssertionError(msg)
-
-    monkeypatch.setattr(fetch_module, "http_fetch", _must_not_refetch)
-    first = format_fetch_result(
-        status=200,
-        final_url="https://example.com/x",
-        content_type="text/plain",
-        body_text="x" * 600,
-        body_bytes=600,
-        truncated=False,
-        redirects=0,
-        method="GET",
-        security="public",
-        warnings=[],
-        body_kind="text",
-        max_chars=200,
-    )
-    token = _extract_token(first)
-    assert token is not None
-    parsed = decode_truncate_token(token)
-    assert parsed is not None
-    assert parsed.kind == "memory"
-    out = await call_async(get_truncated, token, max_chars=200)
-    content, _, _ = out.partition("\n[Truncated")
-    assert content == "x" * len(content)
-    assert 0 < len(content) <= 200
-
-
 async def test_get_truncated_memory_chains() -> None:
     from plyngent.tools.truncate_token import truncate_generic