feat(ui): absorb button in peek, preserve newlines, demote promoted items

Stream peek now shows absorb button for unpromoted entries. Promoted
items in stream show demote instead of delete. d double-tap demotes
any card_type entity regardless of view. Parsers preserve newlines
from Shift+Enter. Absorb popup truncates to first non-empty line.

internal/parse/grammar_test.go

@@ -94,6 +94,11 @@ func TestParse(t *testing.T) {
 		{"inline desc", "body text // inline desc", "body text", "note", nil, sp("inline desc"), nil, nil, nil, false, false, nil, ""},
 		{"url no split", "http://example.com // should not split", "http://example.com // should not split", "note", nil, nil, nil, nil, nil, false, false, nil, ""},
 
+		// Multiline body preserves newlines
+		{"multiline body", "hello\nworld", "hello\nworld", "note", nil, nil, nil, nil, nil, false, false, nil, ""},
+		{"multiline with tags", "line one #ops\nline two", "line one\nline two", "note", nil, nil, nil, []string{"ops"}, nil, false, false, nil, ""},
+		{"title multiline body", "|my title\nfirst line\nsecond line", "first line\nsecond line", "note", sp("my title"), nil, nil, nil, nil, false, false, nil, ""},
+
 		// Edge cases
 		{"empty input", "", "", "", nil, nil, nil, nil, nil, false, false, nil, "empty"},
 		{"only glyph", "-", "", "", nil, nil, nil, nil, nil, false, false, nil, "empty body"},