feat: add per-workflow model assignment configuration

skills/run/SKILL.md

@@ -121,6 +121,49 @@ ${MEMORY_LESSONS}"
 fi
 ```
 
+#### 0c. Model Configuration
+
+Read model assignment from `.archeflow/config.yaml` and resolve the model for each archetype based on the current workflow. Per-workflow overrides take precedence over per-archetype overrides, which take precedence over the default.
+
+```bash
+CONFIG=".archeflow/config.yaml"
+
+# Read default model
+DEFAULT_MODEL=$(grep -A1 '^models:' "$CONFIG" 2>/dev/null | grep 'default:' | sed 's/.*default:\s*//' | tr -d '"' | head -1)
+DEFAULT_MODEL="${DEFAULT_MODEL:-sonnet}"
+
+# Resolve model for a given archetype and workflow
+# Usage: resolve_model <archetype> <workflow>
+resolve_model() {
+  local arch="$1" wf="$2" model=""
+
+  # Check per-workflow per-archetype override
+  model=$(sed -n "/workflows:/,\$p" "$CONFIG" 2>/dev/null \
+    | sed -n "/${wf}:/,/^    [a-z]/p" \
+    | grep -A1 "archetypes:" | grep "${arch}:" \
+    | sed "s/.*${arch}:\s*//" | tr -d '"' | head -1)
+  [[ -n "$model" ]] && echo "$model" && return
+
+  # Check per-workflow default
+  model=$(sed -n "/workflows:/,\$p" "$CONFIG" 2>/dev/null \
+    | sed -n "/${wf}:/,/^    [a-z]/p" \
+    | grep 'default:' | sed 's/.*default:\s*//' | tr -d '"' | head -1)
+  [[ -n "$model" ]] && echo "$model" && return
+
+  # Check per-archetype override
+  model=$(sed -n "/^  archetypes:/,/^  [a-z]/p" "$CONFIG" 2>/dev/null \
+    | grep "${arch}:" | sed "s/.*${arch}:\s*//" | tr -d '"' | head -1)
+  [[ -n "$model" ]] && echo "$model" && return
+
+  # Fall back to default
+  echo "$DEFAULT_MODEL"
+}
+
+# Example: EXPLORER_MODEL=$(resolve_model explorer "$WORKFLOW")
+```
+
+Use `resolve_model` when spawning each agent to pass the correct model. The resolved model can be included in the `agent.start` event data for cost tracking.
+
 ---
 
 ### 1. Plan Phase