chore: scaffold aura workspace and wire the skills dev-cycle

Cargo workspace aura-core -> aura-engine -> aura-cli (bin `aura`) plus nodes/ for hot-reloadable cdylib node crates. Crate bodies are intentionally API-free; types arrive from the first spec. Adds the skills profile (.claude/dev-cycle-profile.yml), the project CLAUDE.md with the eight domain invariants, and the design-ledger skeleton.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Cargo.toml

@@ -0,0 +1,21 @@
+# aura — a "game engine for traders": a Rust framework + playground to author
+# trading nodes, backtest them deterministically and in parallel, compose them
+# fractally, and freeze a validated strategy into a standalone bot.
+#
+# Workspace split is driven by the cdylib hot-reload boundary: `aura-core` is the
+# shared contract that BOTH the engine and every hot-reloadable signal/node
+# cdylib link against. Add crates only when a boundary proves real.
+
+[workspace]
+resolver = "3"
+members = [
+    "crates/aura-core",
+    "crates/aura-engine",
+    "crates/aura-cli",
+]
+
+[workspace.package]
+edition = "2024"
+version = "0.1.0"
+license = "proprietary"
+publish = false