Story: Asset-class-agnostic Market Simulator client: shared IR/FX config UX

The Market Simulator client is asset-class-agnostic. One tree builder, one selection walk, and one new/edit/delete dispatch serve every generation-config kind; the kind of the selected node is derived once and used by every action. One embedded generation-config editor framework (provenance/instrument/process tabs, preview charts, Simple/Advanced parameter table) is parameterised by kind instead of copied per asset class. The process-parameter rows are data-driven for every asset class from its parameter-definitions table, replacing the FX editor's hardcoded rows. A new asset class is a config table, a parameter-definitions table, and one registration — the window and the editor framework are not copied again.

The IR curve work (IrCurveEditor, the tree rows, the config CRUD in the Market Simulator) was carried out by copy-adapting the FX implementation. The copy-paste already produced a defect: observed 2026-09-03, deleting an IR curve config from the tree sends the FX delete request (delete_fx_spot_generation_config_request) because onDeleteClicked's feed branch is hardcoded to FX; the FX handler silently no-ops on the unknown id, so the delete appears to succeed and the config stays in the tree and keeps publishing. The same copy-paste has also produced divergence: the IR process-parameter rows are driven by the yield_curve_process_parameter_definitions table (data-driven labels added 2026-08-31), while the FX editor hardcodes its parameter rows ("κ (reversion speed)") — two different implementations of the same table.

The copy-paste produced a further defect in the IR editor, observed during the BK PR review (PR #2000, 2026-09-04): the price-source vintage lock does not disable initial_rate on the Simple parameter page. updatePriceSourceEnablement() disables the Advanced page's initialRateSpin_ correctly, then walks the Simple page's rows matching cell text against the parameter name "initial_rate" — but the Simple page's cells show the short label ("Initial rate"), so the match never fires. Re-entering Simple mode via the toggle also does not re-run the enablement. The shared editor base this story builds reads the parameter name from the model, so the lock lands in the data-driven row keyed on parameter_name instead of matching display text.

Verified 2026-09-03 against the tree on feature/bk-feature-test-scenario. Parallel per-asset-class code in MarketSimulatorWindow.cpp:

• buildFeedItem(fx) vs buildIrCurveFeedItem(ir) — two tree row builders.
• pairsUnderIndex vs irCurvesUnderIndex; selectedFxPairs vs selectedIrCurves — parallel selection walks over the fxPairs_=/=irCurves_ member maps.
• openFxEditorForNew/Edit vs openIrCurveEditorForNew/Edit — parallel editor openers.
• editEntity dispatches correctly by map membership; onDeleteClicked does not — the defect above.

Parallel editor code:

• IrCurveEditor.cpp was copy-adapted from FxSpotRateEditor.cpp: both embed provenance/instrument/process scaffolding, preview charts, and a Simple/Advanced parameter table in the Market Simulator's right panel.
• IR parameter rows: data-driven via ClientYieldCurveProcessParameterDefinitionModel and the definitions table. FX parameter rows: hardcoded in FxSpotRateEditor.cpp. One of these implementations should serve both.

Scope note: the per-entity client stacks (Client*Model, *Controller, *MdiWindow, *DetailDialog) and the service-layer per-entity code are codegen-generated; their duplication is generative and is the codegen template's business, not this story's. The hand-written window/editor layer above them is the target.

• MarketSimulatorWindow derives the selected node's kind once; the new/edit/delete actions dispatch through one path. The delete-dispatch defect class (IR action sending an FX request) is gone.
• One tree-row builder and one selection walk serve every config kind; adding a config kind adds no per-kind branch to the window.
• One embedded generation-config editor framework serves FX pairs and IR curves. The parameter rows are data-driven for both asset classes; the FX editor's hardcoded rows are replaced.
• A new asset class plugs in with a config table, a parameter-definitions table, and one registration. The window and the editor framework are not copied.
• Client feed control-plane code (folder start/stop fan-out, per-config start/stop loops) stays with Feed lifecycle harmonization: asset-class-agnostic feed control-plane, which already owns it; this story covers the config CRUD, tree, and editor paths only.

Abandoned at sprint 25 close. The Qt client that this story targets was removed in sprint 25 (Retire Qt and emit the UI metadata to TypeScript).