feat: module 10 spellgrid

SpellGrid capstone: Part I's card engine and Part II's grid engine joined at
three seams (rules -> aura data, hazard victims -> one destroy Sequence,
Sequence end -> write text, remove the dead, reparse). Three levels with
scripted solutions, a naive-timing test via a harness-only hook that
reverses the END_OF_PHASE list, CLIs in both tracks, the BATTLECRY IS DOUBLE
Expansion Drop, SpellGrid cards and words in course/cards and the catalog,
level schema cards/hand, and tools staging/copying of module levels.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

course/10-spellgrid/reference/rust/.course.json

@@ -0,0 +1 @@
+{ "track": "rust", "engineDirs": ["src/engine"], "contentDirs": ["src/content", "cards"], "module": "10" }