feat: add task-orchestration plugin

[milkomida77]

Summary

Adds a task-orchestration plugin for multi-agent task routing with anti-duplication and quality gates.

What's included

• plugin.json — plugin metadata
• agents/task-router.md — routes tasks to specialized agents using keyword scoring, checks a SQLite registry to prevent duplicate assignments, and delegates with bounded scope
• skills/quality-gate.md — post-completion verification: file-change validation, test execution, secret scanning, build check, and scope check

How it differs from agent-orchestration

The existing agent-orchestration plugin focuses on agent improvement and context management. This plugin focuses on the task lifecycle: receiving work, preventing duplicate assignments, routing to the right specialist, and verifying completion with evidence-based quality gates.

Key patterns

• Anti-duplication registry: SQLite + SequenceMatcher at 55% threshold catches near-duplicate tasks before they create conflicts
• Keyword-based routing: Lightweight scoring that maps task descriptions to agent capabilities without requiring embeddings
• Quality gates: Five-step verification (file diff, tests, secrets scan, build, scope check) before any task is marked done
• 30-minute heartbeat: Periodic check for stale assignments and idle agents

Extracted from a production system running 57 agents across 10,000+ tasks over 6 months.

Source: guardian-agent-prompts