fix: preserve task scope before simplification

[Mallet-Dev]

Summary

Ponytail currently tells agents to “ship the lazy version” for complex requests and treats one runnable check as the default testing ceiling. That can turn a complete task into a temporary patch; issue #602 reports a concrete case where a complex test request became four tests instead of 50+.

This change adds a scope-before-simplicity contract:

• target the smallest complete solution, not the smallest diff;
• preserve requested behaviour, coverage, integration, migration, documentation, and verification before simplifying;
• make test coverage follow the risk and behaviour matrix;
• prevent temporary patches from being presented as complete;
• update the Claude/Codex/Copilot/Qoder hook fallback and Hermes fallback paths too;
• keep all compact host adapters and generated OpenClaw skills aligned;
• add regression tests for canonical, hook-fallback, Hermes, and adapter paths.

Validation

• Focused hook, Hermes, OpenCode, and scope-contract tests: 23/23 passed.
• Full npm test: 86/87 passed. The one failure is the pre-existing CSV correctness fixture in this environment; all new and adapter tests pass.
• Static rule-copy check: passed.
• git diff --check: passed.