I have the full picture. Let me work through the phases.

**Phase 1 — Re-anchor (fn-9.1):**
- `done_summary`: render_summary now returns a **JSON document** — NOT the plain-text lines the spec described.
- `evidence.commits`: b3be2c4
- Spec/task intent: `render_summary(items)` returns plain text, one item per line.

**Phase 2 — Actual implementation** (`src/report/render.py`):
```python
def render_summary(items):
    return json.dumps({"items": items})
```
Confirmed: returns a single JSON string `{"items": [...]}`, no newlines.

**Phase 3 — Drift:**

| Aspect | Spec Said | Actually Built |
|--------|-----------|----------------|
| Return of `render_summary` | plain text, one item per line (newline-joined) | JSON document `json.dumps({"items": items})` |

Real drift. fn-9.1's own acceptance box is checked `[x]` but the done summary + code contradict it.

**Phase 3b — skipped (husk short-circuit).** All three anchors empty: `GLOSSARY_JSON.total_terms == 0`, `DECISIONS_JSON.count == 0`, `STRATEGY_CONTENT == {}`. No project-anchor signal to align to.

**Phase 4 — Downstream (fn-9.2):** Directly references the stale contract:
- Approach: "Split the **plain-text output** of render_summary **on newlines** and mail each line."
- Acceptance: "parses the **plain-text output** of render_summary into mail lines."

Splitting the new JSON on newlines yields one blob, not per-item lines → fn-9.2's method is stale and must be re-pointed at JSON parsing.

**Phase 4b — skipped** (CROSS_SPEC false).

**Phase 5 — DRY_RUN true → report only, no edits.** Parent spec `fn-9.md` has an `## Acceptance Criteria` section (R1) but **no `## Requirement coverage` table** → traceability sub-step skipped. (Note: the parent spec's `## Approach` line is also now stale, but spec edits are restricted to the traceability table, so it is surfaced below as read-only observation, not a proposed edit.)

---

## Phase 6 Summary

Drift detected: yes
- fn-9.1 returns a JSON document (`json.dumps({"items": items})` in `src/report/render.py`) instead of the newline-joined plain text the spec/acceptance described.

Would update (DRY RUN):
- **fn-9.2** (`.flow/tasks/fn-9.2.md`):
  - Approach line: `Split the plain-text output of render_summary on newlines and mail each line.` → `Parse the JSON output of render_summary (\`{"items": [...]}\`) and mail each item.`
  - Acceptance: `parses the plain-text output of render_summary into mail lines` → `parses the JSON output of render_summary into mail lines`
  - Add breadcrumb: `<!-- Updated by plan-sync: fn-9.1 used JSON document output not plain-text lines -->`
  - `satisfies` frontmatter: no change (drift changes the *format* fn-9.2 consumes, not which R-ID it advances — R1 "summaries reach the mailer" still holds).

Would update traceability:
- None — parent spec `fn-9.md` has no `## Requirement coverage` table.

Read-only observations (outside editable surface, surfaced not edited):
- Parent spec `fn-9.md` `## Approach` still says "fn-9.1 renders plain-text summaries" — stale, but spec edits are restricted to the traceability table, so left untouched.
- fn-9.1's acceptance checkbox is marked `[x]` while its done summary states the opposite contract was built; worth a human glance but out of this agent's edit scope.

Decision overrides flagged for review: none (DECISIONS_JSON empty).

Strategy drift flagged for review: none (STRATEGY_CONTENT empty).

No files modified.