feat(FN-401): blocker note — planner/reviewer prompts live in Fusion platform, not sase worktree

Commits merged:
- docs(FN-401): blocker note — planner/reviewer prompts live in Fusion platform, not sase worktree

Files changed:
docs/clarification/FN-401-blocker.md | 50 ++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

Fusion-Task-Id: FN-401

docs/clarification/FN-401-blocker.md

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+# FN-401 Blocker — Planner/Reviewer Prompt Deltas, Rubric v1 Alignment
+
+**Status:** Cannot execute at sase worktree layer. Handoff required.
+
+## What the task asks for
+
+Land prompt-only deltas so that:
+
+1. The **planner spec template** and the **reviewer prompt** both reference the SAME canonical 9-item rubric v1 (literal published by CPO), byte-identical.
+2. Both reference rubric items by item number (1–9) so reviewer FAILs can cite "item N" and planners can self-check pre-submission.
+3. Reviewer is instrumented to emit **per-item PASS/FAIL** output (not aggregate) for the first run.
+4. **Canary cycle:** FN-396 routes through the new planner→reviewer cycle; per-item output captured; clean PASS across all 9 items lifts the FN-399 → FN-398 → FN-397 chain.
+
+## Why it cannot land in this worktree
+
+The artifacts named in the acceptance criteria are **Fusion platform internals**, not sase-repo code:
+
+- "Planner spec template" — used by the planning model when invoking `fn_review_spec`. Not present in this worktree.
+- "Reviewer prompt" — used by the reviewer model (`pi-claude-cli/claude-haiku-4-5`) when scoring spec submissions. Not present in this worktree.
+- "Reviewer instrumentation" — output-shape change in the Fusion engine's review pipeline.
+- "Canary cycle" — triggering FN-396 through a modified pipeline is a Fusion engine action, not a worktree action.
+
+Exhaustive search across `.fusion/`, `apps/`, `packages/`, `docs/`, `scripts/`, root configs, and `.fusion/agents/{cpo,cto,qa,…}/{instructions,soul}.md` returned no rubric-v1 literal, no planner template file, and no reviewer prompt file. The `.fusion/agents/cpo/instructions.md` covers product funnel routing only — no rubric content.
+
+The worktree boundary explicitly excludes editing Fusion platform code; read-only exceptions cover only `.fusion/memory/`, `.fusion/tasks/*/PROMPT.md`, `.fusion/tasks/*/task.json`, and `.fusion/tasks/*/attachments/`.
+
+## Pre-conditions not met
+
+The PROMPT.md itself states: *"BLOCKED on CPO publishing the canonical 9-item rubric literal."* Project memory (`MEMORY.md:241-252`) confirms: *"Rubric v1 signed off 2026-05-16; CTO staging prompt deltas. Re-review under new rubric before intervention design starts."* The literal text has been signed off conceptually but is not committed to any file readable from a sase worktree.
+
+## What is needed to unblock
+
+1. **CPO** publishes the canonical 9-item rubric v1 literal — either:
+   - Committed to `.fusion/memory/rubric-v1.md` in the sase repo (worktree-readable), or
+   - Committed directly into Fusion platform planner/reviewer prompt files (out-of-scope for sase worktree executors).
+2. **CTO / Fusion platform owner** edits the planner spec template + reviewer prompt with the literal, byte-identical.
+3. **Fusion platform owner** adds per-item PASS/FAIL emission to the reviewer.
+4. **Fusion engine** routes FN-396 through the new cycle to capture per-item output.
+5. On clean PASS, lift FN-399 → FN-398 → FN-397 (held by agent-f1516562).
+
+## Suggested next step
+
+Reassign FN-401 to a Fusion-platform context (CTO `agent-403a540b` per the staging note), or wait for CPO to commit `rubric-v1.md` into `.fusion/memory/` so a sase-layer doc-only staging delta becomes possible. Notify agent-f1516562 once the rubric literal is available so the gate on FN-399 → FN-398 → FN-397 can be re-evaluated.
+
+## Provenance
+
+- Sase worktree: `/home/s/fusion/project/sase/.worktrees/noble-fern`
+- Branch: `fusion/fn-401`
+- Base commit: `2083d7f` (FN-400)
+- Authored by: executor `agent-403a540b` during recovery session, 2026-05-16.