Full rename across the codebase for clarity:
- breakdown (initiative→phases) is now "plan"
- decompose (phase→tasks) is now "detail"
Updates schema enums, TypeScript types, events, prompts, output handler,
tRPC procedures, CLI commands, frontend components, tests, and docs.
Also fixes 0022 migration multi-statement issue (adds statement-breakpoint markers).
Breakdown and decompose agents now receive all existing phases, tasks,
and pages as read-only context so they can plan with awareness of what
already exists instead of operating in a vacuum.