Read external WordPress subagent graphs in bounded chunks

[chubes4]

Problem

External WordPress setup currently embeds read-opencode-subagent-graph.php in one wp eval call and expects the complete portable graph in one control-transport response. Real agent graphs with embedded instructions, skills, and references can exceed bounded relay response limits even though ordinary WP-CLI calls work.

The control transport is intentionally opaque and may impose smaller per-response bounds than the graph schema. HTTP-specific compression or chunking does not belong in the generic runtime.

Expected behavior

The external graph reader should transfer the graph through multiple bounded, deterministic wp eval responses and reconstruct the exact JSON locally before projection. Local WordPress behavior and the graph schema must remain unchanged.

Acceptance

• A graph larger than an individual transport response projects successfully.
• Every external transport response stays under a deterministic bound.
• The graph is generated without persistent temporary state or credentials.
• Malformed, inconsistent, or incomplete chunks fail closed.
• Existing external WordPress and local projection tests remain green.

AI assistance

GPT-5.6-sol via OpenCode diagnosed the live bounded-transport failure and drafted this issue. Chris Huber remains responsible for the report and resulting changes.

[chubes4]

Live verification through the restored persistent relay confirmed that application-level chunks advance correctly, but an individual completed relay response can stall indefinitely inside the sandbox despite the transport client socket timeout. Because each chunk read is deterministic and side-effect-free, the external graph reader also needs a process-level deadline and bounded retry per chunk.

AI assistance: GPT-5.6-sol via OpenCode ran the live SecEx verification and identified the retry boundary. Chris Huber remains responsible for the follow-up.