Add code-grounded brainstorm for data-provider and accounting improvements

.claude/skills/meridian-brainstorm/brainstorm-history.jsonl

@@ -7,3 +7,4 @@
 {"session_date": "2026-03-27", "mode": "Domain-Focused", "themes": ["Script debugger (step/watch/breakpoint)", "Script run history and result diffing", "Security Master access in QuantScript (Securities global)", "Script output export (PDF/Parquet/Excel/HTML)", "Script expression REPL", "Venue-specific L3 calibration profiles (VenueCalibrationPriors)", "TCA report: execution cost attribution", "Multi-day queue state continuity (carry-state)", "Dark pool / hidden liquidity estimator", "Zero-downtime rolling upgrade orchestration", "Geo-distributed collection by exchange timezone", "Split-brain detection and recovery"], "ideas_count": 12, "track": "G-H-I", "notes": "Second round of Track G-I brainstorm. TCA Report identified as highest-leverage institutional positioning item. VenueCalibrationPriors and SplitBrainDetector identified as platform bets. Script REPL flagged as surprise high-leverage small-effort item. Sequencing: REPL + SecurityMaster -> TCA Report -> RunHistory + VenueCalibration -> SplitBrain -> RollingUpgrade + DarkPool + GeoDistributed + Debugger + MultiDayContinuity."}
 {"session_date": "2026-06-25", "mode": "Domain-Focused", "themes": ["Provider Setup Wizard with Live Certification", "Hot-Reload Provider Re-Registration", "Credential Vault with Encrypted Persistence", "Runtime Failover Chain Editor", "Per-Provider Partial Config Mutation API", "Ingestion Session Continuity on Restart", "Provider Capability Browser in Data Workspace"], "ideas_count": 7, "document_updated": null, "notes": "Fresh domain covering runtime provider lifecycle management — an unexplored area in all prior sessions. Platform bets: Hot-Reload Re-Registration (ConfigWatcher already exists, ProviderRegistry.RegisterStreamingFactory already supports replace) and Per-Provider Partial Config Mutation (ConfigStore.PatchAsync primitive). Recommended sequence: Capability Browser (S) -> Partial Config API (M) -> Hot-Reload (M) -> Failover Editor (S) -> Setup Wizard (M) -> Credential Vault (M) -> Session Continuity (L)."}
 {"session_date": "2026-07-01", "mode": "Competitive / Open Exploration", "themes": ["live/paper TCA best-execution report pack", "Alpaca live broker adapter (IExecutionGateway)", "reconciliation break-resolution agent (MCP + CoS gates)", "custodian/broker statement connector library (IB Flex, OFX/CSV profiles)", "DuckDB analytics workbench + /api/query", "Python meridian client package (promoted)", "W6 backtesting studio evidence loop (manifest + run comparison)", "LEAN/NautilusTrader data-feed bridge", "governed investor report delivery portal-lite", "data-cost savings meter"], "ideas_count": 10, "document_updated": "docs/product/high-value-code-brainstorm-2026-07.md", "notes": "Market-researched prioritization session. Signals: TCA now mandatory infrastructure (~$2.8B market), Arcesium productizing Reconciliation Agent, LEAN BYO-data pain, Databento/Polygon pricing validates self-hosted economics. Sequencing: cost meter + TCA + IB Flex connector first; DuckDB -> Python package; Alpaca adapter feeding W7; W6 studio slice; recon agent after connector coverage."}
+{"session_date": "2026-07-05", "mode": "Domain-Focused", "themes": ["streaming provider WebSocketProviderBase unification + honest connection status", "canonical symbol-resolution spine (resolver into BackfillWorkerService, cross-validation symbol fix, CanonicalSymbolRegistry convergence)", "unified data-quality model + browser Data Quality dashboard", "backfill feedback loop (raise OnProgressUpdate, typed SLA metadata in AutoGapRemediationService, configurable remediation provider)", "provider failure & rate-limit hardening (DataSourceRegistry swallowed exceptions, typed RateLimitException, streaming rate-limit tracking)", "mark-to-market wiring (DailyPortfolioPricingProjector -> governed drafts -> true NAV, NavAttributionService aggregation fix)", "automated journal drafts in close cockpit (dividends/fees/withholding via AutomatedJournalDraftProjector)", "period-close closing entries + retained-earnings roll", "one ledger spine (unify Meridian.Ledger projectors with ILedgerJournalStore, F#/C# enum ordinal guard)", "fill-to-ledger durability fix in LedgerPostingConsumer (TryWrite drops fills under backpressure)"], "ideas_count": 10, "document_updated": "docs/product/data-provider-accounting-brainstorm-2026-07.md", "notes": "Code-grounded deep dive into provider + accounting subsystems via fresh exploration. Headline findings: Meridian.Ledger projector library (pricing, amortization, tax lots, multi-currency, waterfalls, automated drafts, shadow NAV) has zero live callers so NAV is at cost; provider layer fractured (only Alpaca/Polygon on WebSocketProviderBase, three disconnected symbol mechanisms, three overlapping data-quality paths). Cross-cutting theme: silent failure. Sequencing: fill durability + backfill feedback + resolver fixes first; mark-to-market next; drafts/closing entries; ledger + symbol spine unification last."}

docs/generated/repository-structure.md

@@ -1766,6 +1766,7 @@ Meridian-main
 │   │   ├── waves-2-4-operator-readiness-addendum.md
 │   │   └── web-ui-development-pivot.md
 │   ├── product
+│   │   ├── data-provider-accounting-brainstorm-2026-07.md
 │   │   ├── deferred-expansion-boundaries.md
 │   │   ├── high-value-code-brainstorm-2026-07.md
 │   │   ├── implementation-todo-list.md