fix(intake): enforce scoped interactive boundaries

[ignorejjj]

Summary / 概述

Closes #46.

• Make every visible intake reply a hard user-turn boundary; mixed text + tool responses are suppressed instead of executing behind a displayed question.
• Split scoped, read-only research discussion from benchmark launch planning, remove intake shell access, and enforce canonical user-approved paths across Read/Glob/Grep.
• Stage immutable launch plans and require a later explicit confirmation handled by the CLI controller, so go cannot trigger a model rewrite.
• Reset filesystem authority on resume/reset, redact persisted tool/compaction data, and reject unsafe conversation/experience paths.
• Honor the documented nested llm: project configuration during intake preflight and update English/Chinese docs and READMEs.

Linked issue / 关联 issue

Closes #46

Type of change / 改动类型

• 🐞 Bug fix / 缺陷修复 (fix)
• ✨ Feature / 新功能 (feat)
• 📝 Docs / 文档 (docs)
• ♻️ Refactor / 重构 (refactor)
• ✅ Tests / 测试 (test)
• 🔧 Chore / build / CI (chore)

How was this tested? / 如何验证？

.venv/bin/python -m ruff check src tests
.venv/bin/python -m pytest -q
# 489 tests collected; full suite passed with 6 optional-environment skips

git diff --check
# clean

Real CLI E2E against a local scripted OpenAI-compatible endpoint:
- Chinese future-intent question: 1 model request, then returned to `you ›`
- Mixed visible text + sibling Read: tool suppressed; sibling content never read/persisted
- Authorized Read: 2 model requests (tool-only, then answer); persisted result redacted
- Pure sibling Read: BLOCKED by path policy; secret absent from model request/history
- Staged LaunchExperiment: `go` entered the outer Research Contract with request count still 1; final run was cancelled with `n`

Checklist / 检查清单

• PR title follows Conventional Commits (e.g. fix(config): ...). / PR 标题遵循 Conventional Commits 规范。
• The change is focused and reasonably small. / 改动聚焦且体量合理。
• I ran the relevant tests locally (python tests/test_*.py) and they pass. / 我已在本地运行相关测试并通过。
• Docs / examples updated if behavior or config changed. / 若行为或配置有变更，已同步更新文档/示例（含 README.zh-CN.md）。
• No secrets, API keys, or tokens are included in the diff. / diff 中不包含任何密钥、API key 或 token。