#13891: docs: Add Angel OS alignment and strategy context

**AI-assisted PR.** Angel OS is OpenClaw + adoption of the Angel OS Constitution. This PR adds minimal docs so contributors and forks see how Angel OS relates to OpenClaw and the strategy (Constitution-first, minimal changes). Longer-term goal: an immutable seed prompt, open for discussion and refinement. - **What:** New docs: ANGEL_OS_ALIGNMENT.md, ANGEL_OS_CONSTITUTION_SEED.md, plus one README sentence with link. - **Why:** Raise awareness and open discussion; no runtime or config changes. - **Testing:** Docs only. Lightly tested: docs reviewed for accuracy. - **Understanding:** The added docs describe Angel OS alignment and a minimal Constitution seed; no code or behavior change. <!-- greptile_comment --> <h2>Greptile Overview</h2> <h3>Greptile Summary</h3> Adds documentation for Angel OS alignment with OpenClaw, introducing two new files that describe the relationship between OpenClaw and the Angel OS Constitution. The changes include: - A reference in `README.md` pointing to the new Angel OS documentation - `ANGEL_OS_ALIGNMENT.md` explaining the strategy and vision for Angel OS (OpenClaw + Angel OS Constitution) - `ANGEL_OS_CONSTITUTION_SEED.md` summarizing core principles (Answer 53, Ultimate Fair split, Prime Directives) The documentation is clear that no runtime or behavior changes are included—this is purely informational content for contributors and forks. **Issues found:** - Internal doc link format in `ANGEL_OS_ALIGNMENT.md:10` should follow Mintlify convention (root-relative without file extension) <h3>Confidence Score: 4/5</h3> - This PR is safe to merge with one minor link formatting fix - Score reflects documentation-only changes with no runtime impact. The single syntax issue (incorrect doc link format) is minor and easily corrected. Content is well-structured and aligns with the stated goal of adding minimal context about Angel OS. - docs/ANGEL_OS_ALIGNMENT.md needs the link format corrected on line 10 <!-- greptile_other_comments_section --> _{(2/5) Greptile learns from your feedback when you react with thumbs up/down!} **Context used:** - Context from `dashboard` - CLAUDE.md ([source](https://app.greptile.com/review/custom-context?memory=fd949e91-5c3a-4ab5-90a1-cbe184fd6ce8)) <!-- /greptile_comment -->