Fix interleaving timetable parse

[huppd]

• Fix crash on interleaved timing tables: read_logfile now routes each row to the table matching its header's column count (with fallback to earlier headers) instead of assuming rows between two headers all belong to the first one; this previously caused a hard sys.exit(1) crash
• Unmatched rows now log a warning and are skipped, rather than aborting the whole parse
• Fixed a related pre-existing bug: the parser was silently dropping the last matching line of every log file; regenerated the affected reference/add JSON fixtures accordingly
• Added a focused regression test + small dedicated fixture for the interleaving fix, plus a minimal interleaved splice in the existing timing_example_1.txt fixture

---

This PR were developed with AI assistance (Claude Code). Please review accordingly rather than assuming sole human authorship.