docs(session): add restart-safe recovery workflow

Context:

- codex cli 중단 후에도 작업 품질과 맥락을 안정적으로 복구하기 위해

Changes:

- docs/00~07, 90 문서 세트 추가/정리

- commit convention 문서 및 .gitmessage-session.txt 템플릿 추가

- scripts/session/recover-context.sh 추가

- package.json에 session:recover 스크립트 추가

Validation:

- npm run session:recover

Session-State: session recovery docs, template, and script are in place

Session-Next: apply this commit format to feature and refactor commits

Session-Risks: legacy commits before this change do not include session trailers

scripts/session/recover-context.sh

@@ -0,0 +1,54 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+cd "${ROOT_DIR}"
+
+RECENT_COUNT="${1:-8}"
+
+print_section() {
+  local section_title="$1"
+  local next_section="$2"
+  if [[ -f docs/90_current_state.md ]]; then
+    if [[ -n "${next_section}" ]]; then
+      awk "/^## ${section_title}\$/{flag=1} /^## ${next_section}\$/{flag=0} flag" docs/90_current_state.md
+    else
+      awk "/^## ${section_title}\$/{flag=1} flag" docs/90_current_state.md
+    fi
+  fi
+}
+
+echo "== Session Recovery =="
+echo "repo: ${ROOT_DIR}"
+echo "branch: $(git rev-parse --abbrev-ref HEAD)"
+echo "head: $(git log -1 --pretty=format:'%h %s (%ci)')"
+echo
+
+echo "== Working Tree =="
+git status --short
+echo
+
+echo "== Recent Commits (${RECENT_COUNT}) =="
+git log --oneline --decorate -n "${RECENT_COUNT}"
+echo
+
+echo "== HEAD Commit Body =="
+git show -s --format=%B HEAD
+echo
+
+echo "== HEAD Changed Files =="
+git show --name-status --pretty=format: HEAD | sed '/^$/d'
+echo
+
+if [[ -f docs/90_current_state.md ]]; then
+  echo "== docs/90_current_state.md =="
+  print_section "DONE" "NEXT"
+  echo
+  print_section "NEXT" "RISKS"
+  echo
+  print_section "RISKS" "CHANGED FILES"
+  echo
+  print_section "CHANGED FILES" "QUICK VERIFY"
+  echo
+fi