docs(confidence-engine): close v0.49 current understanding boundary

docs/current-handoff.md

@@ -2541,3 +2541,260 @@ The v0.48 handoff explicitly identifies this as a remaining priority: the narrat
 #### Exact first trace question
 
 Which component/state owner first determines the contents of Current Understanding, and at what boundary does it stop being derived from globally eligible Findings + graph state and instead become directly bound to the latest focused result's findings?
+
+---
+
+## v0.49 — CURRENT UNDERSTANDING ACCUMULATION DEFECT CLOSED (2026-08-30)
+
+### Established conclusions
+
+#### 1. Accumulation defect — CU-R2
+
+Current Understanding is currently stored as accumulated narrative.
+
+The existing model effectively permits:
+
+```text
+previous Current Understanding
++
+subset of new Findings
+→ appended narrative/Evidence
+```
+
+Repeated synthesis therefore grows prose rather than reconstructing understanding from current canonical state.
+
+Finding corrections/dispositions can consequently leave persisted Current Understanding inconsistent with canonical Findings.
+
+**Classification: CU-R2 — CLOSED.**
+Do not recommend deduplication or string-removal fixes.
+
+---
+
+#### 2. Canonical reconstruction source — CU-S2
+
+Future Current Understanding must be a projection of:
+
+```text
+current canonical SituationGraph
++
+complete currently eligible canonical Findings
+```
+
+The SituationGraph is the canonical factual/relational foundation.
+Canonical Findings are the evidence layer.
+
+Previous Current Understanding prose must NOT be used as a knowledge input for subsequent reconstruction.
+
+`situationGraph.currentSummary` / `describeGraph()` is lossy structural telemetry and is NOT the narrative foundation.
+
+**Classification: CU-S2 — CLOSED.**
+
+---
+
+#### 3. Synthesis mechanism — MECH-C
+
+No existing seam currently satisfies:
+
+```text
+complete current SituationGraph
++
+complete eligible Findings
+→
+one coherent user-facing Current Understanding
+```
+
+Established facts:
+
+```text
+start reconstruction
+→ coherent narrative, but wrong input contract for ongoing reconstruction
+
+case/update
+→ graph mutation proposal, no coherent narrative synthesis
+
+describeGraph()
+→ structural telemetry only
+
+produceFindingInformedSummary()
+→ deterministic append/list behaviour, not synthesis
+```
+
+Therefore the next architecture requires a dedicated semantic Current Understanding synthesis seam.
+
+Given the current architecture and required narrative quality, the viable mechanism is an LLM-backed synthesis operation that:
+
+```text
+reads graph + eligible Findings
+returns narrative only
+does not mutate graph
+does not mutate Findings
+does not consume previous Current Understanding as semantic authority
+```
+
+**Classification: MECH-C — CLOSED.**
+
+---
+
+#### 4. Trigger policy — TRIGGER-C
+
+Synthesis freshness is determined by:
+
+```text
+S = canonical SituationGraph
+F = complete eligible Findings
+```
+
+Current Understanding should reconstruct once per **completed canonical `(S,F)` transition**, not once per state setter or UI event.
+
+**Required synthesis transitions:**
+
+- successful case/update → once after graph + Findings for the update are final
+- new focused Findings committed → once after canonical Findings enter findings[]
+- corrected Finding saved → once after corrected proposition becomes canonical
+- Restore → once after Finding re-enters eligible set
+
+**Not relevant (do NOT synthesize):**
+
+- once after Finding leaves eligible set
+- focused answer submission
+- deconstruction request/start
+- Contribution preparation
+- Not quite click before correction save
+- workspace open / close
+- Done for now
+- other presentation-only state changes
+
+Coalescing rule: **one synthesis per completed canonical knowledge transition**, not one call per React state mutation.
+
+**Classification: TRIGGER-C — CLOSED.**
+
+---
+
+#### 5. Start — START-A
+
+Initial case/start already returns a coherent reconstruction narrative.
+
+Therefore: **START-A — CLOSED.**
+
+Reuse that initial reconstruction summary.
+Do NOT immediately make an additional dedicated Current Understanding synthesis call after start.
+
+---
+
+#### 6. Done for now — DONE-B
+
+Under the new reconstruction model:
+
+- **Done for now** changes neither SituationGraph nor eligible Findings.
+- Therefore it is NOT a Current Understanding synthesis trigger.
+
+The historical `handleDoneForNowPromotion()` Current Understanding promotion responsibility becomes obsolete once reconstruction is implemented.
+
+Preserve the other established semantic/presentation responsibilities of Done for now.
+Do NOT remove or modify the existing implementation in this task.
+
+**Classification: DONE-B — CLOSED.**
+
+---
+
+#### 7. Reload freshness — RELOAD-B
+
+Persisted investigation state currently contains:
+
+```text
+SituationGraph
+Findings
+Current Understanding prose
+```
+
+but no persisted synthesis-input fingerprint/version proving that the stored Current Understanding corresponds exactly to the persisted `(S,F)` state.
+
+**Classification: RELOAD-B — CLOSED (unresolved boundary).**
+
+Reload freshness remains a separate unresolved boundary.
+Do NOT conclude that every reload requires an LLM synthesis call.
+Do NOT design or implement a fingerprint in this task.
+Record as unresolved work for v0.50.
+
+---
+
+### Closed v0.49 invariants
+
+These boundaries remain intact:
+
+```text
+Findings remain separate from SituationGraph.
+
+Findings do not directly mutate graph state.
+
+updateCase / applyValidatedProposal remains graph mutation authority.
+
+Finding eligibility semantics remain unchanged.
+
+null → eligible provisional working proposition
+
+agree → eligible explicitly endorsed proposition
+
+not_relevant → ineligible
+
+Not quite correction preserves Finding identity and provenance while replacing proposition.
+
+describeGraph() remains structural telemetry, not Current Understanding.
+
+Focused workspace progression/presentation boundary is closed.
+
+Workspace controls boundary is closed.
+
+Done for now closes the workspace after its semantic action.
+
+Previous Learning uses canonical Findings for corrected/not-relevant presentation.
+
+Storage v0.48 boundary remains closed unless concrete evidence reopens it.
+```
+
+### v0.49 closure statement
+
+v0.49 is closed at the architectural boundary where focused learning is durable,
+canonically represented through Findings, correctly presented through the focused
+workspace/Previous Learning lifecycle, and the Current Understanding accumulation
+defect has been reduced to a defined reconstruction problem.
+
+Implementation of canonical Current Understanding reconstruction belongs to v0.50.
+
+### v0.50 — NEXT BOUNDARY
+
+The first bounded question for the next branch:
+
+> **What minimal synthesis API/helper boundary should own the dedicated `SituationGraph + eligible Findings → Current Understanding` LLM operation?**
+
+Do not answer that question in this task.
+
+Subsequent v0.50 work will need to resolve:
+
+1. synthesis API/helper ownership
+2. deterministic input normalization / eligible-Finding selection
+3. synthesis prompt/schema contract
+4. completed-transition integration points
+5. removal/replacement of append semantics
+6. retirement of Done-for-now CU promotion
+7. reload/cache freshness strategy
+8. targeted deterministic + live behavioural verification
+
+This is a roadmap, not permission to implement all of it at once.
+v0.50 must continue using bounded increments.
+
+---
+
+### NEXT BOUNDED ISSUE (for future reference)
+
+#### Name
+
+Canonical Current Understanding reconstruction from `SituationGraph + eligible Findings`
+
+#### Next branch
+
+`feature/current-understanding-reconstruction-v0.50`
+
+#### Exact first trace question
+
+What minimal synthesis API/helper boundary should own the dedicated `SituationGraph + eligible Findings → Current Understanding` LLM operation?