feat: add decision.point event type, decision logger, and run replay script

- archeflow-decision.sh: convenience wrapper for logging PDCA decision points
- archeflow-replay.sh: timeline view and weighted what-if replay for recorded runs
- archeflow-event.sh: add decision.point usage example
- archeflow-dag.sh: render decision.point events in DAG output

lib/archeflow-decision.sh

@@ -0,0 +1,48 @@
+#!/usr/bin/env bash
+# archeflow-decision.sh — Log a PDCA decision point for run replay / effectiveness analysis.
+#
+# Appends a decision.point event to .archeflow/events/<run_id>.jsonl with:
+#   phase, archetype (agent + data.archetype), input, decision, confidence, ts (via event layer)
+#
+# Usage:
+#   ./lib/archeflow-decision.sh <run_id> <phase> <archetype> '<input>' '<decision>' <confidence> [parent_seq]
+#
+# Examples:
+#   ./lib/archeflow-decision.sh 2026-04-06-auth check guardian \
+#     'diff + proposal risks' 'needs_changes' 0.82 7
+#   ./lib/archeflow-decision.sh 2026-04-06-auth act "" 'route findings' 'send_to_maker' 0.9
+#
+# confidence: 0.0–1.0 (orchestrator-estimated certainty in the recorded choice)
+#
+# Requires: jq (via archeflow-event.sh)
+
+set -euo pipefail
+
+LIB_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+if [[ $# -lt 6 ]]; then
+  echo "Usage: $0 <run_id> <phase> <archetype> '<input>' '<decision>' <confidence> [parent_seq]" >&2
+  exit 1
+fi
+
+RUN_ID="$1"
+PHASE="$2"
+ARCH="$3"
+INPUT="$4"
+DECISION="$5"
+CONF_RAW="$6"
+PARENT="${7:-}"
+
+if ! [[ "$CONF_RAW" =~ ^[0-9]*\.?[0-9]+$ ]]; then
+  echo "Error: confidence must be a number (e.g. 0.85)" >&2
+  exit 1
+fi
+
+DATA=$(jq -cn \
+  --arg a "$ARCH" \
+  --arg i "$INPUT" \
+  --arg d "$DECISION" \
+  --argjson c "$CONF_RAW" \
+  '{archetype:$a, input:$i, decision:$d, confidence:$c}')
+
+exec "$LIB_DIR/archeflow-event.sh" "$RUN_ID" decision.point "$PHASE" "$ARCH" "$DATA" "$PARENT"