merge: context-safe claude code alignment

chore(release): 升级context-safe版本到0.4.6

chore(context-safe): 收尾文档与验证断言

feat(context-safe): 增加compact no-op断路保护

test(context-safe): 调整rehydration bundle预算断言

feat(context-safe): 增强会话恢复索引信息

feat(context-safe): 增加语义化preserved tail保留策略

feat: preserve context-safe api invariants in kept tails

feat: persist context-safe summary boundary metadata

chore: bump version to 0.4.5

fix: backport bilingual retention tiers

fix: stop dropping messages during canonical sync

fix: publish report-aware policy runtime dependency

fix: backport packaged install flow

fix: prefer packaged context-safe installs