After /clear, Claude Code sometimes loses awareness of custom agent types
and falls back to 'general-purpose'. This happens because the model doesn't
re-read .claude/agents/ after context reset.
Added <available_agent_types> sections to:
- execute-phase.md: lists all 12 valid GSD agent types with descriptions
- plan-phase.md: lists the 3 agent types used during planning
The explicit listing in workflow instructions ensures the model always has
an unambiguous reference to valid agent types, regardless of whether
.claude/agents/ was re-read after /clear.
Fixes#949
6536214a3a