Spike: PTY-based Claude Code integration with multi-agent concurrency

Proves that spawning `claude -p` in a pseudo-terminal from Rust gets Max
subscription billing (apiKeySource: "none", rateLimitType: "five_hour")
instead of per-token API charges. Concurrent agents run in parallel PTY
sessions with session resumption via --resume for multi-turn conversations.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.ignore

@@ -0,0 +1,4 @@
+frontend/
+node_modules/
+.story_kit/
+store.json