docs: add agent trace for Sharing is Caring badge

trace.md

@@ -0,0 +1,28 @@
+# Soap Lab — Agent Trace
+
+## Example: Agentic Recipe Optimiser
+
+**Input:** "300g coconut oil, 400g olive oil — optimise this recipe for me"
+
+**Step 1 — Parse:** coconut oil: 300g, olive oil: 400g
+
+**Step 2 — Score:**
+- Cleansing: 27.9 (HIGH — target 12-22)
+- INS: 103.5 (LOW — target 136-165)
+
+**Step 3 — Iteration 1:**
+- Cleansing too high → transfer 35g coconut → olive
+- Recipe: coconut 265g, olive 435g
+
+**Step 4 — Rescore:**
+- Cleansing: 24.6 (still high, improved)
+- INS: 97.6 (still low)
+
+**Step 5 — AI Explanation:**
+- Model: Qwen/Qwen2.5-3B-Instruct via Featherless AI
+- Explains changes in plain English to user
+
+## Architecture
+- Chemistry engine: deterministic Python (no AI)
+- AI layer: explanation only, never calculates
+- Model: Qwen2.5-3B-Instruct (Tiny Titan eligible)