v0.8.0 - Risk-tiered Agent readiness profiles

What shipped

• Machine-readable read-only, draft-only, and state-changing readiness profiles.
• Profile-specific total and per-area minimum scores, allowed and required tool effects, approval requirements, and launch-blocker policies.
• Opt-in profile input for the GitHub Action; existing min-score, fail-below, and fail-on-blockers behavior is unchanged when no profile is selected.
• Fail-closed handling for unknown or malformed profiles, missing tool-effect metadata, mismatched Agent Card metadata, disallowed capabilities, and missing approval on external-state tools.
• One honest Agent Card per profile: the read-only example passes, while the existing draft and state-changing examples retain their original 12/20 and 15/20 scores and blockers.
• English and Simplified Chinese threat-model guidance, JSON Schema, and 87 deterministic tests.

中文说明

• 新增 read-only、draft-only、state-changing 三类机器可读生产就绪 Profile。
• 每类 Profile 分别定义总分、分项最低分、允许/必需工具影响、审批要求与上线阻塞项策略。
• GitHub Action 新增可选 profile 参数；不启用时，原有参数行为完全不变。
• 未知或损坏 Profile、缺失工具影响、卡片声明不一致、越界能力与外部状态工具缺少审批均会 fail closed。
• 每类 Profile 都有真实示例；不会为了通过门禁篡改已有 Agent 分数或隐藏阻塞项。
• 提供完整中英文威胁模型说明、JSON Schema 与 87 项确定性测试。

Closes #12.

Adoption evidence / 采用证据

• Content OS main CI consumes public @v0: its 12/20 compatibility score passes, while the draft-only profile correctly exposes a 12/14 total gap, a 1/2 tool-permission gap, and three launch blockers.
• Content OS 主分支真实使用公开 @v0：兼容分数门禁通过，但 draft-only Profile 如实暴露总分、工具权限与三个上线阻塞项。