fix(runtime): fall back on invalid archive routing proposals

[Grivn]

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Before opening a PR, read the Contributing Guide, 贡献指南, and the Development and Verification Guide / 开发和验证指南.
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本仓库接受 Bug 修复、兼容性适配、现有能力增强、性能或体验优化和维护类 PR。全新能力、Provider、持久化格式或安全边界变更必须先提 Issue 并获得维护者确认。 / This repository accepts bug fixes, compatibility work, improvements to existing capabilities, performance or UX optimization, and maintenance. New capabilities, Providers, persistence formats, or security-boundary changes require prior maintainer approval in an Issue.
外部贡献者的仅文档类 PR 不直接接受；请先提 Issue 讨论。维护者的发布说明与文档维护不受此限制。 / Documentation-only PRs from external contributors are not accepted directly; open an Issue first. Maintainer release notes and documentation maintenance are exempt.

摘要 / Summary

Runtime capacity archival now falls back for a routing proposal that fails Host validation, including later batches that restart source numbering. The Host applies each proposal only after complete validation, preserves earlier valid batches, and archives exact originals while keeping model excerpts within their character budget.

关联 Issue 或背景 / Related Issue or Context

Fixes #235

涉及区域 / Affected Areas

• Host 激活、Headless 或 bundle / Host activation, Headless, or bundle
• 运行时记忆 / Runtime Memory
• 项目档案 / Project Documents
• 记忆空间或 Provider / Memory Spaces or Providers
• 子 Agent 或 Agent 工作流 / Subagent or Agent workflow
• Web UI 或对话交互 / Web UI or conversation interaction
• 设置、存储或安全 / Settings, storage, or security
• CLI、RPC、命令或工具 / CLI, RPC, commands, or tools
• 安装、更新或发布 / Installation, update, or release
• 测试、构建或文档 / Tests, build, or documentation
• 其他（请说明）/ Other (explain below)

PR 类型 / PR Type

• 面向用户的功能或行为变更 / User-facing feature or behavior change
• Bug 修复 / Bug fix
• 增强或优化 / Enhancement or optimization
• 兼容性适配 / Compatibility change
• 维护或重构 / Maintenance or refactor
• 测试或构建 / Tests or build

最新代码确认 / Latest Codebase Confirmation

• 我已基于最新 main 分支开发，或在提交前已 rebase 或合并最新 main。 / I developed from the latest main, or rebased or merged the latest main before submitting.

同步命令 / Sync command:

git fetch origin main — latest base 1e19caf40f0bf37edf678c3d829f2398ab28792a.

AI 编码披露 / AI Coding Disclosure

• 完全 AI 编码：全部编程改动由 AI 产出，并由贡献者接受和审查。 / Fully AI-coded: AI produced all programming changes, which the contributor accepted and reviewed.
• 部分 AI 辅助：AI 帮助编写或修改了部分内容。 / Partially AI-assisted: AI helped write or modify part of the change.
• 未使用 AI 编码辅助。 / No AI coding assistance was used.

使用的 AI 模型 / AI model used:

GPT-6 Astra, max reasoning.

使用的编码 Agent 工具 / Coding Agent tool used:

Codex desktop.

仓库规范检查 / Repository Rules

• 未修改 DSH 官方源码，未让 tsconfig 指向 DSH 源码 checkout，仅使用正式的 @deepseek-ai/* NPM 契约。 / I did not modify DSH source or point tsconfig at a DSH source checkout, and used only published @deepseek-ai/* NPM contracts.
• Client 与 Host 边界仍以浏览器安全的 src/host/protocol.ts 为准，没有在两侧重复定义 wire DTO。 / The Client and Host boundary still uses browser-safe src/host/protocol.ts as the source for wire DTOs.
• 持久化格式、RPC 权限、路径或凭据处理的变更包含兼容或拒绝路径、安全分析和相应测试。 / Changes to persistence formats, RPC authority, paths, or credentials include compatibility or rejection paths, security analysis, and tests.
• 没有提交 token、密钥、私有记忆、未脱敏日志或生成的 lib/ 文件。 / I did not commit tokens, credentials, private memory, unredacted logs, or generated lib/ files.
• 用户可见文案和长期文档已同步维护中文与英文版本，命令、配置键和路径保持一致。 / User-facing copy and long-lived documentation are synchronized in Chinese and English, with matching commands, configuration keys, and paths.
• 会改变发布制品或其元数据的 PR 已添加 changeset；仅测试、CI 或站点文档变更可不添加。 / A PR that changes a published artifact or its metadata includes a changeset; test-only, CI-only, and site-documentation-only changes may omit one.
• 新增和修改的代码、注释、文档、提交信息不含 emoji。 / New and modified code, comments, documentation, and commits contain no emoji.

兼容性与数据安全 / Compatibility and Data Safety

No storage-format, Provider contract, configuration, credentials, path, or RPC authority changes. Fallback uses only the existing eligible catalog and preserves earlier valid route batches. The current chunk is validated in a temporary map; invalid or partially valid proposals cannot leak destinations. Exact source bytes remain independent of truncated model excerpts, and caller cancellation still stops before archival writes.

Provider-write preflight and compensation are handled separately in PR #243 for issue #240; this PR does not change Provider recovery semantics or promise a distributed transaction. Root alone receives a patch changeset.

本地验证 / Local Validation

执行的命令 / Commands run:

pnpm verify
pnpm verify:plugins
MNEMON_NATIVE_TEST_CLI=/opt/homebrew/bin/mnemon pnpm --filter dsh-mnemon-source-memory-spaces exec vitest run tests/native-integration.spec.ts
pnpm exec vitest run tests/subagent.spec.ts
pnpm e2e:serve --runtime-routing --strategy-extensions
pnpm verify:docs

结果摘要 / Result summary:

All pass. Root: 936 tests passed, 5 opt-in live-model tests skipped; final coordinator run: 95 tests. Workspace tests, types, deterministic builds, real Headless activation, public entries and package validation pass. Standalone verification covers 16 independent plugins and 17 packed artifacts, including all three optional enhancements together. Real Mnemon 0.2.7 created/wrote/recalled/forgot a disposable store.

Regression fails before the fix. Added checks cover missing sources, duplicate/out-of-range/noninteger indexes, invalid destinations, empty/failed proposals, preservation of earlier valid chunks, exact original content and bounded excerpts. Existing cancellation checks remain passing. Model replies are deliberately scripted to reproduce the malformed proposal; transport, tool calls, Host, Source plugins, WebUI and Native storage are real.

用户可见变更证据 / Local Feature Evidence

证据 / Evidence:

Reproduction steps, bilingual results and screenshots.

With two active Native spaces and all three Strategy enhancements, the first routing batch receives and returns [1, 2]; the second receives [3] but returns [1]. Before: the exact coverage error appears, no archive is written, and Runtime stays at 1,278/1,600 bytes. After restarting the same fixture with the fix and retrying the same entry: fallback succeeds, all three complete originals are visible in Native, and Runtime commits the pending entry at 913/1,600 bytes.