docs(skills): add managed skills to README, restore developer.md orch…

[haofeif]

Summary

• README: Add "Managed Skills" section documenting cao skills CLI commands (list, add, remove, add --force), provider delivery table, and skill update instructions
• developer.md: Restore "Multi-Agent Communication" section that was removed by feat: Add support for skills #145 — handoff/assign instructions should remain inline in the agent profile, not only in builtin skills that require cao init
• docs/skills.md: Remove Q CLI references (deprecated), clarify builtin skill seeding behavior, use consistent language for how providers pick up skill changes

Context

PR #145 (skills feature) moved the handoff/assign/send_message instructions from developer.md into a cao-worker-protocols builtin skill. However:

• The skills frontmatter field was never implemented, so the reference was removed in the final squash
• The inline instructions were not restored, leaving a gap
• The README had no documentation for cao skills commands

Test plan

• Docs-only change — verify README renders correctly
• Verify developer.md has the Multi-Agent Communication section restored
• Verify docs/skills.md no longer references Q CLI

[haofeif]

@patricka3125 can you please help to review this ? It is just the documentation update.

Why restore the Multi-Agent Communication section in developer.md

PR #145 removed the inline handoff/assign instructions from developer.md and replaced them with a skills: [cao-worker-protocols] frontmatter reference. However, in the final squash commit, the skills frontmatter field was also removed because per-profile skill scoping was never implemented. The net result is that developer.md lost its orchestration instructions with nothing replacing them.

The cao-worker-protocols skill still exists in the package, but it only reaches the skill store if the user runs cao init — which is not part of the Quick Start flow.

Even when seeded, skills are loaded lazily and depend on the agent deciding to load them based on description matching. The handoff/assign instructions are not optional domain knowledge — they are core to how workers behave in a multi-agent session. A worker that doesn't know to call send_message after an assign task will silently fail to return results to the supervisor.

And i think in the existing ways of running cao, we dont have to run cao init, so i restore the developer.md instruciton back, for users who do not run cao init they can have seamless experience

[patricka3125]

Hey @haofeif thanks for the documentation follow up. LGTM. and yeah I decided to scope down #145 and defer the skills frontmatter support into a future change. The changes to the developer.md shouldve been reverted so thanks for catching this quickly

[fanhongy]

when the cao-server starts (be explicit)