feat(plugin): adapt to Claude Code 2.1.265-2.1.280, bump v1.47.0

[bug-ops]

Summary

Adapts rust-agents to Claude Code 2.1.265–2.1.280 after reviewing the changelog, the system prompt changes over the same range, and the current subagent, skill, agent-team, hook, and plugin references. Bumps the plugin and marketplace to 1.47.0.

Changed

• Report delivery in auto mode (2.1.271). In auto mode a subagent returns its result through a SubagentHandback call, and plain text at the end of a run is not delivered. The affected texts (the continuous-improvement subagents engine, the three sdd-integration.md references, and the handoff protocol) no longer ask for the report in the final message. The handoff protocol now names where the block goes: SendMessage for a teammate, SubagentHandback when available, otherwise the final message.
• team-develop Step 6.5. When the host provides ReportFindings (the desktop app), the bundled code-review skill runs inline in the lead's context and no task notification arrives. The step now covers both modes and uses medium when inline.
• Opus 5.5 (2.1.280). rust-architect, rust-critic, rust-security-maintenance, rust-arch-analyst, and rust-security-analyst move from claude-opus-5 to claude-opus-5-5, which has a lower price and stronger code review. effort: high stays explicit because the model defaults to medium.
• Teammate spawns. Since 2.1.280 the Agent tool suggests isolation: "worktree" when parallel write-capable agents share a checkout. A named spawn with isolation starts a plain subagent outside the team, so team-develop and team-debug now forbid it.
• Marketplace entry. Since 2.1.265, /plugin → Installed and claude plugin details prefer the marketplace entry over plugin.json. Its description and keywords now match plugin.json, and the stale ci-analyst keyword is replaced with live-testing and research-protocol.
• README: unattended continuous-improvement runs recommend Claude Code 2.1.280 or later, which fixed lost background reports and hanging -p runs.

Fixed

• The continuous-improvement preflight printed an empty "Last cycle journal" instead of none when the journal directory was missing, because the pipeline status came from tail.
• The root README and continuous-improvement still labeled rust-arch-analyst and rust-security-analyst as sonnet, although both have run on Opus since 1.45.0.

Notes for reviewers

• The following were checked and are unaffected:
  • The git refusals added during skills in 2.1.273 apply only to the bundled commit and PR skills.
  • All preflight commands are covered by allowed-tools, so the 2.1.271 auto mode change for inline shell commands does not affect them.
  • The removed TaskOutput tool and Monitor persistent option are not used.
  • Teammates still ignore skills:, so the startup Skill() calls stay.
• effort: medium on rust-architect and rust-arch-analyst is an untried way to cut cost. This PR keeps high on all five Opus agents.

Verification

• claude plugin validate --strict --json ./rust-code and claude plugin validate --strict --json . pass on Claude Code 2.1.280 without warnings.
• The workflow's version check reports 1.47.0 in all six locations.
• The fixed journal preflight prints none when no journal directory exists.