chore: add ralph infrastructure for rah-light strip-down

- prd.json with 15 user stories for phases 1-3
- prompt.md customized for deletion workflow
- progress.txt initialized

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

ralph/ralph-once.sh

@@ -0,0 +1,63 @@
+#!/bin/bash
+set -e
+
+# Ralph Single Iteration (Human-in-Loop Mode)
+# Usage: ./ralph/ralph-once.sh
+#
+# Runs one iteration of Ralph interactively, allowing you to observe and steer
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
+PRD_FILE="$SCRIPT_DIR/prd.json"
+PROGRESS_FILE="$SCRIPT_DIR/progress.txt"
+PROMPT_FILE="$SCRIPT_DIR/prompt.md"
+
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+echo "  🐕 Ralph Single Iteration (Interactive)"
+echo "━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━"
+
+# Verify required files exist
+if [ ! -f "$PRD_FILE" ]; then
+    echo "❌ Error: $PRD_FILE not found"
+    echo "Create prd.json with your user stories first."
+    exit 1
+fi
+
+if [ ! -f "$PROMPT_FILE" ]; then
+    echo "❌ Error: $PROMPT_FILE not found"
+    exit 1
+fi
+
+# Initialize progress file if needed
+if [ ! -f "$PROGRESS_FILE" ]; then
+    echo "# Ralph Progress Log" > "$PROGRESS_FILE"
+    echo "Started: $(date)" >> "$PROGRESS_FILE"
+    echo "" >> "$PROGRESS_FILE"
+fi
+
+echo "📋 PRD: $PRD_FILE"
+echo "📝 Progress: $PROGRESS_FILE"
+echo ""
+
+cd "$PROJECT_DIR"
+
+# Build the full prompt with current state
+FULL_PROMPT="$(cat "$PROMPT_FILE")
+
+---
+
+## Current State
+
+### prd.json
+\`\`\`json
+$(cat "$PRD_FILE")
+\`\`\`
+
+### progress.txt
+\`\`\`
+$(cat "$PROGRESS_FILE")
+\`\`\`
+"
+
+# Run Claude Code with prompt via stdin
+echo "$FULL_PROMPT" | claude --print --allowedTools "Edit,Write,Read,Bash,Glob,Grep"