pi-subagents: renderProjectContext still emits pi ≤0.85's block shape, so a relocated child's own project context no longer matches Pi's

[gotgenes]

renderProjectContext in packages/pi-subagents/src/session/project-context.ts still emits pi ≤0.85's <project_context> shape, so the block a relocated or portable child renders for itself no longer matches the one pi ≥0.86 writes — while its doc comment claims it does, "byte for byte".

Current behavior

The replica produces an extra blank line below the opening tag and another above the closing tag:

<project_context>

Project-specific instructions and guidelines:

<project_instructions path="/parent/AGENTS.md">
# AGENTS

Parent house rules.
</project_instructions>

</project_context>

pi 0.86.1 writes neither. Its renderProjectContext joins the lead-in and each <project_instructions> block with "\n\n" and the section wrapper contributes the surrounding newlines, so the real block is:

<project_context>
Project-specific instructions and guidelines:

<project_instructions path="/parent/AGENTS.md">
# AGENTS

Parent house rules.
</project_instructions>
</project_context>

I generated that from the 0.86.1 dist directly:

pnpm view @earendil-works/pi-coding-agent@0.86.1 dist.tarball
# then, against a scratch install of 0.86.1:
node -e 'import("./node_modules/@earendil-works/pi-coding-agent/dist/core/system-prompt.js")
  .then(m => console.log(m.buildSystemPrompt({
    cwd: "/parent",
    customPrompt: "x",
    contextFiles: [{ path: "/parent/AGENTS.md", content: "# AGENTS\n\nParent house rules." }],
  })))'

Expected behavior

The replica renders whichever shape the running pi writes, or the doc comment stops claiming byte-identity it no longer has.

Why it matters

The module's doc comment is the contract:

Render context files as Pi's <project_context> block, byte for byte.

Pi writes a lead-in sentence and separates each <project_instructions> block with a blank line; matching it exactly is what keeps a block this package renders indistinguishable from one buildSystemPrompt wrote.

That is now false on 0.86, which is the version the peer range (>=0.81.0, unbounded) admits and the one I am running.

The consumers are exactly the two children ADR 0010 and ADR 0009 route here: a child a WorkspaceProvider relocated, and a portable child. Nothing anchors on the extra blank lines today — projectContextStart's lead-in guard tolerates both offsets — so I read this as low severity. It is a correctness claim that has quietly gone stale rather than an observed failure, and I would rather fix the claim than discover later what was relying on it.

Relationship to #958

Same root cause — pi 0.86's prompt reshape — but a different code path. #958 is about the anchors that read an inherited prompt; this is about the block this package writes. Keeping them separate so #958's fix stays reviewable.

Environment

• pi 0.86.1 (pi --version)
• packages/pi-subagents devDependency pinned at @earendil-works/pi-coding-agent@0.84.4
• Peer range >=0.81.0

[gotgenes]

Implemented in 5efc8b9, which switches renderProjectContext's own-context block from pi ≤0.85's shape to pi ≥0.86's section-shaped block — confirmed against a real 0.86.1 install, the 0.87.1 tarball, and Pi's main checkout, so a relocated child's own project context now matches what Pi itself writes.

• 5efc8b9 — render a relocated or portable child's project context in pi 0.86's block shape (fixes this issue's title defect).
• 4484832 — wrap a portable child's appended prompt in pi 0.86's <addendum> section, a sibling gap in buildPortablePrompt found during the same investigation.

User-visible behavior: a relocated or portable subagent's own project-context block, and a portable child's appended prompt, now render in the block shape pi ≥0.86 uses, instead of the stale ≤0.85 shape.
No breaking change — this is an internal prompt-rendering fix with no public API change.

Releasing as pi-subagents v21.7.7.