feat: add planner-agent, remove STATE.md append from dev-agent

- Remove write_state_entry/append_state_log from dev-agent (#10)
- Add planner-agent.sh: rebuilds STATE.md from git history + closed
  issues, then gap-analyses against VISION.md to create backlog
  issues (#6, #7)
- Add planner-poll.sh: cron wrapper with lock + memory guard

STATE.md is now solely owned by the planner — one compact snapshot
rebuilt each run, not an ever-growing append log.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

planner/planner-poll.sh

@@ -0,0 +1,51 @@
+#!/usr/bin/env bash
+# =============================================================================
+# planner-poll.sh — Cron wrapper for planner-agent
+#
+# Runs weekly (or on-demand). Guards against concurrent runs and low memory.
+# =============================================================================
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+FACTORY_ROOT="$(dirname "$SCRIPT_DIR")"
+
+# shellcheck source=../lib/env.sh
+source "$FACTORY_ROOT/lib/env.sh"
+
+LOG_FILE="$SCRIPT_DIR/planner.log"
+LOCK_FILE="/tmp/planner-poll.lock"
+
+log() { echo "[$(date -u +%Y-%m-%dT%H:%M:%S)Z] $*" >> "$LOG_FILE"; }
+
+# ── Lock ──────────────────────────────────────────────────────────────────
+if [ -f "$LOCK_FILE" ]; then
+  LOCK_PID=$(cat "$LOCK_FILE" 2>/dev/null || true)
+  if [ -n "$LOCK_PID" ] && kill -0 "$LOCK_PID" 2>/dev/null; then
+    log "poll: planner running (PID $LOCK_PID)"
+    exit 0
+  fi
+  rm -f "$LOCK_FILE"
+fi
+echo $$ > "$LOCK_FILE"
+trap 'rm -f "$LOCK_FILE"' EXIT
+
+# ── Memory guard ──────────────────────────────────────────────────────────
+AVAIL_MB=$(free -m | awk '/Mem:/{print $7}')
+if [ "${AVAIL_MB:-0}" -lt 2000 ]; then
+  log "poll: skipping — only ${AVAIL_MB}MB available (need 2000)"
+  exit 0
+fi
+
+log "--- Planner poll start ---"
+
+# ── Run planner agent ─────────────────────────────────────────────────────
+"$SCRIPT_DIR/planner-agent.sh" 2>&1 | while IFS= read -r line; do
+  log "  $line"
+done
+
+EXIT_CODE=${PIPESTATUS[0]}
+if [ "$EXIT_CODE" -ne 0 ]; then
+  log "poll: planner-agent exited with code $EXIT_CODE"
+fi
+
+log "--- Planner poll done ---"