v1.5.0: invalid-INS one-byte re-frame + explicit discard logging

Residual CONCAT mis-frames (4gmodem/A55_sim2/S21p_sim2) traced to a silent
5-byte drop at an invalid-INS T=0 header (0x0f 00 a4 08 04). Drop only the
stray leading byte and re-frame the remaining four via _replay so the real
command (00 a4 08 04 02 2f 00 -> 61 1c) is recovered.

- _note_discard()/_consume_first(): every consumed-but-unemitted byte is
  now logged; idle 0x00/0xFF discards are rate-limited, real data always
  gets an ANN_WARN annotation.
- All read-until-SW loops log skipped non-SW bytes.
- All traces: CONCAT 0; BAD_FCS/GARBAGE 0; test_8/test_7 RESULT OK;
  47/47 unit tests; baseline byte-identical.

History rewritten to a single root commit so no example trace is stored
in the repo (fixtures are local-only, gitignored). README keeps only
generic <trace>.sr placeholders; AGENTS.md retains the fixture names.

__init__.py

@@ -0,0 +1,25 @@
+##
+## This file is part of the libsigrokdecode project.
+##
+## Copyright (C) 2012 Uwe Hermann <uwe@hermann-uwe.de>
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 2 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; if not, see <http://www.gnu.org/licenses/>.
+##
+
+'''
+ISO7816 is a bidirectional, multi-master
+bus using two signals (CLK = serial clock line, DATA = IO data line).
+'''
+
+from .pd import Decoder