I1: run-scenario and both SpellGrid CLIs check moves first and treat any other engine
error as fatal (same text in both tracks); trigger blocks close on error (try/finally,
catch_unwind in Rust); unknown summons rejected. I2, I3, M1-M7, T3, T9a-c, T10a-b.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Engine events carry the nesting depth they were recorded at; the harness
prints the log as an indented tree. New tests test_02_log_tree_shows_nesting
and test_03_log_tree_death_phase; both SpellGrid CLIs print the tree of the
last command's Sequences under a Log: line.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>