Normalize whitespace in grid get_process_output to save tokens

Grid snapshots pad every row to the full terminal width and leave the
bottom of the screen blank, so MCP grid reads carried a lot of dead
whitespace. Add normalizeGridText (CRLF/lone-CR to LF, right-trim each
line, collapse blank runs to a single blank, drop leading/trailing
blanks) and apply it to the grid branch of GetProcessOutput only.
Stream output, raw output, and WaitForPattern matching are untouched.

Resolves the terminal-read newline/token-waste TODO item.

internal/app/ring_test.go

@@ -104,3 +104,44 @@ func TestStripANSIBytesEquivalence(t *testing.T) {
 		}
 	}
 }
+
+func TestNormalizeGridText(t *testing.T) {
+	cases := []struct {
+		name string
+		in   string
+		want string
+	}{
+		{
+			name: "line endings",
+			in:   "one\r\ntwo\rthree",
+			want: "one\ntwo\nthree",
+		},
+		{
+			name: "trailing whitespace",
+			in:   "one   \ntwo\t\t\nthree",
+			want: "one\ntwo\nthree",
+		},
+		{
+			name: "collapse blank runs",
+			in:   "one\n\n\n two\n \n\t\nthree",
+			want: "one\n\n two\n\nthree",
+		},
+		{
+			name: "trim leading and trailing blanks",
+			in:   "\n \n\t\none\n\n",
+			want: "one",
+		},
+		{
+			name: "already clean",
+			in:   "one\n\ntwo\nthree",
+			want: "one\n\ntwo\nthree",
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			if got := normalizeGridText(tc.in); got != tc.want {
+				t.Fatalf("normalizeGridText(%q) = %q, want %q", tc.in, got, tc.want)
+			}
+		})
+	}
+}