helexa#179's application-owned system prompts let tireless shape both ends of
the cc->oc handoff, so the "will a 27B execute an Opus plan" risk becomes a
tunable rather than a hope.
Three prompts, versioned as one set: plan.cc.md tells Claude Code it is writing
for a literal, absent reader; implement.oc.md tells OpenCode to execute exactly
that and report rather than improvise; implement.cc.md covers unplanned issues.
PromptSet::load refuses a mismatched set, and tests assert the prompts mention
every section ChildSpec requires.
The middle is validated, not trusted. plan::validate rejects a plan before any
implementation job is enqueued unless every child carries a runnable acceptance
command (a stopping condition) and a non-empty out-of-scope list (a boundary) --
the two sections a small model needs and a human reader does not. Dangling and
cyclic dependencies are caught too, and implementation_order derives the start
order.
cc uses --append-system-prompt, never --system-prompt: replacing Claude Code's
default discards the tool-use scaffolding that makes it a coding agent. Pin
bumped to 2.1.220, the version this flag surface was verified against.
The oc path depends on helexa#179's passthrough guarantee, which is still open
and unverified for qwen3 arch templating. Stage 5 now opens with a PONG probe
rather than debugging it through a failed implementation run.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DHhHtohxcdk1PL3tfnYJdH
7b8308d34e
