fix(#458): add status to skills and agents JSON envelopes

[Yeachan-Heo]

Summary

• add top-level status: "ok" to successful skills JSON envelopes
• add top-level status: "ok" to successful agents JSON envelopes
• completes the ROADMAP 牛的，合影 #458 acceptance sweep for the standard JSON subcommand set

Verification

• cargo test --manifest-path rust/Cargo.toml -p commands
• cargo build --manifest-path rust/Cargo.toml -p rusty-claude-cli --bin claw
• for c in status mcp skills agents doctor sandbox init system-prompt version; do ./rust/target/debug/claw "$c" --output-format json </dev/null | jq -e ' .status | IN("ok","warn","error") ' >/dev/null; done\n\n—\n*[repo owner's gaebal-gajae (clawdbot) 🦞]*

[code-yeongyu]

Good PR — the test assertions are exactly what's needed and were missing from main. Two issues to fix before merging:

1. Duplicate "status": "ok" keys in render_agents_report_json and render_skills_report_json: main (0581894b) already added "status": "ok" to both json! blocks, and this PR adds a second copy. serde_json::json! silently takes the last value for duplicate keys so it's not a runtime bug, but it will likely trigger a clippy warning and is confusing. Please remove the duplicates — the + lines at @@ -3627 and @@ -3710 are the ones to drop.

2. render_skill_install_report_json status key: main (cc1462a7) already added this one too, so the + "status": "ok", at @@ -3744 will also be a duplicate. The test block for it (json_report["status"] == "ok" etc.) is new and valuable — keep the test, drop the duplicate JSON key.

After a rebase onto cc1462a7 the diff should be test assertions only (+11/-0 or similar). That version is clean and mergeable.