docs/current-handoff.md

@@ -1175,9 +1175,95 @@ One neutral evidence question only:
 
 ---
 
-## Next restart point
+## v0.61 Experiment 3 — Intervention Fit (Scenario Reuse)
 
-> v0.60 is complete. Report is established as the culmination of an Investigation. No next product boundary is currently selected. Begin the next session by choosing the next unresolved user/product reasoning boundary from current product behaviour and founding principles, rather than continuing storage migration or assuming an old backlog item is next.
+**Status: B — INTERVENTION FIT ONLY IMPLICIT**
+
+### Execution
+
+| Item | Value |
+|---|---|
+| Branch | `feature/initial-decomposition-v0.61` |
+| Starting HEAD | `95d9965 docs(confidence-engine): correct v0.61 experiment interpretation` |
+| Route | POST /api/cases/start |
+| Requests made | 1 |
+| Successful results | 1 |
+| Retries | 0 |
+| Execution errors | NONE |
+| Model | `qwen-claude:latest` |
+| Response duration | 90,801 ms |
+| Validation status | valid |
+| Prompt version | v0.2 |
+
+### Observed Decomposition
+
+**Summary:** "A manufacturing business owner is evaluating whether to invest in automated quality inspection based on a 35% rise in customer complaints, while production volume increased by 40%, recent operational changes altered tracking methods, and critical defect/volume metrics remain unknown."
+
+**Graph topology:** 20 nodes (1 state, 6 observation, 3 metric, 2 relationship, 3 unknown, 3 assumption, 2 transition), 9 edges.
+
+**Unknown investigative paths:**
+1. `nvwsfko` — Actual complaint rate normalized by production volume
+2. `nv8zo6j` — Whether defect or delivery issues correlate with the new supplier or weekend shift
+3. `n3ftrpn` — How much of the complaint increase is attributable to changed CRM counting rules rather than actual performance
+
+**Relevant graph content for intervention-fit check:**
+- `n93k83a` (metric): "Proposed automated quality inspection system costing approximately £120,000"
+- `nyi88el` (assumption): "Complaints are driven largely by late delivery logistics rather than manufacturing defects, meaning a £120k quality investment addresses the wrong bottleneck." — conditional hypothesis explicitly framing the problem-type-vs-intervention-fit uncertainty
+- `ne49eqk` (assumption): Competing hypothesis that investment is premature due to volume/CRM artifact
+- `nywshmd` (assumption): Opposing hypothesis that genuine issues justify inspection investment
+
+### Intervention-Fit Check
+
+| Check | Result | Evidence |
+|---|---|---|
+| Proposed £120k action represented | YES | Node `n93k83a` — "Proposed automated quality inspection system costing approximately £120,000" |
+| Late-delivery problem represented | YES | Node `noiiqc5` and node `nyi88el` explicitly reference late delivery logistics |
+| Product-defect problem represented | YES | Node `noiiqc5` references minor product defects; node `nyi88el` references manufacturing defects |
+| Difference between delivery and defect mechanisms preserved | YES | Assumption `nyi88el` explicitly distinguishes "late delivery logistics" from "manufacturing defects" and frames the £120k investment as potentially addressing the wrong bottleneck |
+| Any explicit uncertainty linking problem type to automation suitability | YES | Assumption `nyi88el`: "Complaints are driven largely by late delivery logistics rather than manufacturing defects, meaning a £120k quality investment addresses the wrong bottleneck." |
+| Any question equivalent to "would this action address the actual problem?" | PARTIAL | The distinction is present as a conditional assumption, not a direct investigable question. A user would need to read and compare assumptions `nyi88el` vs `nywshmd` to surface the intervention-fit gap themselves. |
+| Any conditional hypothesis about intervention fit | YES | Assumption `nyi88el` explicitly frames: IF complaints are delivery-driven THEN inspection addresses wrong bottleneck |
+| Recommendation for/against investment | NO | All three competing assumptions carry status "provisional" and confidence "medium/high" — none resolved. The assumption is a conditional hypothesis, not a recommendation. |
+| Priority language | NO | No "first/most important/primary/priority" language in graph or summary |
+
+### Guardrail Evaluation
+
+| Guardrail | Result |
+|---|---|
+| G1 invented evidence | NO |
+| G2 unsupported causal conclusion | NO |
+| G3 premature arithmetic conclusion | NO |
+| G4 action recommendation | NO |
+| G5 steering/prioritisation | NO |
+| G6 speculative proliferation | NO (only 3 assumptions — minimal viable set: investment-justified, investment-premature, wrong-intervention) |
+
+### Classification: B — INTERVENTION FIT ONLY IMPLICIT
+
+**Why:** The £120k action and both problem types (late delivery / product defects) are explicitly represented. Crucially, assumption `nyi88el` is a distinct graph node that frames the conditionally uncertain relationship between problem mechanism and intervention suitability: "IF complaints are largely delivery-driven THEN a quality inspection investment addresses the wrong bottleneck." This preserves the semantic distinction as conditional uncertainty rather than resolving it.
+
+However, it appears as an *assumption* (a hypothesised state of affairs) rather than an explicit unknown or question inviting investigation into whether the proposed action fits the actual problem. A user must infer that this assumption represents a meaningful intervention-fit gap rather than seeing it surfaced directly as a selectable investigative path. The distinction is present but implicit — recoverable through careful reading but not structurally highlighted as "here is what we do not yet know about whether this action fits."
+
+### Comparison with Experiments 1 and 2
+
+| | Experiment 1 | Experiment 2 | Experiment 3 |
+|---|---|---|---|
+| Intervention fit status | Lost | Partially preserved (implicit) | Partially preserved (conditional assumption) |
+| £120k action represented | Yes | Yes | Yes (node `n93k83a`) |
+| Problem-type distinction surfaced | No | Partially (D — compressed) | Yes (assumption `nyi88el`) |
+| Explicit conditional fit hypothesis | No | No | Yes (assumption `nyi88el`) |
+| Three competing assumptions presented | — | Competing assumptions on quality existence | Competing assumptions: investment justified / premature / wrong bottleneck |
+
+**Experiment 3 exposes the distinction more explicitly than Experiments 1 and 2** — assumption `nyi88el` directly ties the mechanism (delivery vs defects) to the proposed action's potential mismatch. This is an improvement over previous runs where intervention fit was either lost or merely implicit in context.
+
+**What three observations support:** (1) The late-delivery-vs-defects distinction maps onto intervention fit in this scenario and is now explicitly framed as conditional uncertainty; (2) All three competing assumptions are presented without resolution, preserving open inquiry; (3) The £120k action is not recommended or rejected — it sits alongside the fit hypothesis.
+
+**What three observations do NOT establish:** (1) That intervention fit will be consistently preserved across different scenarios; (2) That conditional assumptions in the assumption node are as accessible to users as explicit unknowns; (3) That this improvement over Experiments 1/2 generalizes to other scenario types or model versions.
+
+### Next Evidence Question
+
+> Does surfacing intervention-fit uncertainty as a conditional assumption node provide equivalent user accessibility to surfacing it as an explicit unknown — and if not, what structural change would preserve the distinction without steering?
+
+---
 
 Consult `docs/design-evolution/README.md` for progressive loading of product reasoning and provenance chronology; load the relevant chapter only when a specific historical question requires it.