fix(cli,tui): recall real paste content on up-arrow

Large pastes collapse to a placeholder in the composer, but input history
stored the placeholder — so up-arrow recall showed a truncated reference
(CLI) or lost the content entirely (TUI, where the `[[…]]` label has no
backing snip after submit).

Store the expanded content in history instead:
- CLI: `_inline_pastes()` expands `[Pasted text #N -> file]` into the buffer
  before `reset(append_to_history=True)`; also reused by the external editor
  (dedup). History nav suppresses re-collapse of recalled content.
- TUI: `dispatchSubmission` pushes `expandSnips(pasteSnips)(full)`; idempotent
  on label-free text so re-submitting a recalled entry stays stable.

tests/cli/test_cli_external_editor.py

@@ -103,3 +103,41 @@ def test_open_external_editor_sets_skip_collapse_flag_during_expansion(tmp_path)
     # Flag is consumed by _on_text_changed, but since no handler is attached
     # in tests it stays True until the handler resets it.
     assert cli_obj._skip_paste_collapse is True
+
+
+def test_inline_pastes_stores_full_content(tmp_path):
+    """History should recall the actual pasted text, not the placeholder."""
+    cli_obj = _make_cli()
+    paste_file = tmp_path / "paste.txt"
+    paste_file.write_text("line one\nline two", encoding="utf-8")
+    buffer = _FakeBuffer(text=f"[Pasted text #1: 2 lines \u2192 {paste_file}]")
+
+    cli_obj._inline_pastes(buffer)
+
+    assert buffer.text == "line one\nline two"
+    assert buffer.cursor_position == len("line one\nline two")
+    # Skip flag set so the resulting text-change doesn't re-collapse.
+    assert cli_obj._skip_paste_collapse is True
+
+
+def test_inline_pastes_leaves_plain_text_untouched():
+    """No placeholder → buffer text and collapse flag are unchanged."""
+    cli_obj = _make_cli()
+    buffer = _FakeBuffer(text="just a normal message")
+
+    cli_obj._inline_pastes(buffer)
+
+    assert buffer.text == "just a normal message"
+    assert cli_obj._skip_paste_collapse is False
+
+
+def test_inline_pastes_missing_file_keeps_placeholder(tmp_path):
+    """A recalled reference whose file is gone stays as the placeholder."""
+    cli_obj = _make_cli()
+    placeholder = f"[Pasted text #1: 2 lines \u2192 {tmp_path / 'gone.txt'}]"
+    buffer = _FakeBuffer(text=placeholder)
+
+    cli_obj._inline_pastes(buffer)
+
+    assert buffer.text == placeholder
+    assert cli_obj._skip_paste_collapse is False