Task: Rename CIR, OU, and GMM processes to their proper names

Every other short-rate process in this codebase is spelled out (vasicek_process, hull_white_process); cir_process, ou_process, gmm_process, and arithmetic_gmm_process are the remaining bare acronym/initialism names. QuantLib itself spells the first two out (CoxIngersollRossProcess=/=ExtendedCoxIngersollRoss, OrnsteinUhlenbeckProcess; QuantLib has no direct GMM-mixture equivalent to cross-check against, but the same "no bare acronym" convention applies). Rename:

• cir_process → cox_ingersoll_ross_process
• ou_process → ornstein_uhlenbeck_process
• gmm_process → gaussian_mixture_model_process
• arithmetic_gmm_process → arithmetic_gaussian_mixture_model_process

(class, file, test file, header, doc, for each) for consistency.

These acronyms also appear well beyond their process classes themselves, and — unlike a purely internal rename — some of that surface is directly user-visible, so the rename genuinely propagates up to the UI:

• cir: the synthetic_yield_curve_process_types catalog/enum, the ir_curve_generation_config.process_type stored value, process_factory=/=process_parameter_validation, doc references across sprint_23/24. User-visible: IrCurveEditor's kEngines combo shows the raw code \"CIR\" as the selectable item text (only the tooltip spells it out as "Cox-Ingersoll-Ross") — this is the concrete UI gap to fix, not just an internal identifier.
• ou: fx_spot_generation_config.process_type's check constraint (in ('geometric', 'arithmetic', 'ou')), hull_white_process's own docstring (its kappa < 0= degenerate branch is documented as reducing to exactly ou_process's formula — that cross-reference needs updating too), doc references. Qt's ProcessTypeLabel=/ =FxSpotRateEditor already show the fully spelled-out "Ornstein- Uhlenbeck" label for this code, so no UI-visible gap here — only the internal class name changes.
• gmm=/=arithmetic_gmm: these process_type strings are already the spelled-out \"geometric\"=/\"arithmetic\", and =ProcessTypeLabel=/=FxSpotRateEditor already show "Geometric Brownian Motion""Arithmetic Brownian Motion" — so, like ou, no UI-visible gap, only the internal class-name mismatch (a class literally named "Gaussian Mixture Model" implementing what the UI correctly calls Geometric/Arithmetic Brownian Motion, since a single-component Gaussian mixture applied multiplicatively additively is GBM/ABM — the class name should reflect what it actually is at the code level, GMM, while the UI-facing Geometric/Arithmetic Brownian Motion labelling for the common single-component case stays as-is).

Scope this task to identifier/type renames the codebase controls directly. Decision: the stored process_type string values also change to their full spelled-out form — cir → cox_ingersoll_ross, ou → ornstein_uhlenbeck (gmm=/=arithmetic_gmm don't apply, since those stored values are already \"geometric\"=/\"arithmetic\", not the class-name acronym). This includes the reference-data catalogue code (=CIR → COX_INGERSOLL_ROSS in ores_synthetic_yield_curve_process_types_tbl), the SQL check constraints referencing cir=/=ou=/=CIR, and every C++/UI string literal and comment that names the short code — a genuine data/wire migration, not just an internal symbol rename.

• cir_process → cox_ingersoll_ross_process, ou_process → ornstein_uhlenbeck_process, gmm_process → gaussian_mixture_model_process, arithmetic_gmm_process → arithmetic_gaussian_mixture_model_process (class, header, source, tests, for each) throughout ores.analytics.quant (including process_factory=/=process_parameter_validation).
• Every other codebase reference to any of these classes/types (Qt's IrCurveEditor=/=ProcessTypeLabel=/=FxSpotRateEditor, ores.ore domain, hull_white_process's own cross-reference to ou_process, doc knowledge pages) updated to match.
• IrCurveEditor's kEngines combo shows a spelled-out label for the CIR entry (e.g. "Cox-Ingersoll-Ross"), not the raw \"CIR\" code — mirroring the pattern ProcessTypeLabel=/=FxSpotRateEditor already use for FX's engine combo.
• Stored process_type values also renamed to their full form: cir → cox_ingersoll_ross, ou → ornstein_uhlenbeck (gmm=/=arithmetic_gmm don't apply — see Goal). Covers the ores_synthetic_yield_curve_process_types_tbl catalogue row code (CIR → COX_INGERSOLL_ROSS), SQL check constraints (synthetic_yield_curve_process_types_create.sql, synthetic_fx_spot_generation_configs_create.sql, synthetic_ir_curve_generation_configs_create.sql), populate scripts, and every C++/Qt string literal comparing against these codes (process_factory, process_parameter_validation, ProcessTypeLabel, FxSpotRateEditor, IrCurveEditor).
• Full build and test suite green after the rename (this is a rename, not a behaviour change — no test assertions should need updating beyond identifier/value names).

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

1. Renamed the four process files (header/source/tests) in ores.analytics.quant via git mv, then renamed the class, include-guard, and every in-repo reference (process_factory, process_parameter_validation, hull_white_process's cross-reference, tests) via targeted sed passes.
2. Decision (superseding the original "keep stored value as-is" framing in the Goal): stored process_type values also become the full spelled-out form — cir=/=CIR → cox_ingersoll_ross=/ =COX_INGERSOLL_ROSS, ou → ornstein_uhlenbeck. Updated the SQL check constraints and populate scripts (dev DB rebuilt from scratch via db recreate, so no migration script needed) and every C++/Qt string literal comparing against these codes.
3. IrCurveEditor's engine combo previously stored the raw code as both display text and value (addItem(code) / currentText()). Refactored to the code/label split FxSpotRateEditor already uses (EngineInfo{code, label}, addItem(tr(label), code), currentData() for the underlying value) so the combo shows "Cox-Ingersoll-Ross" while process_type still stores COX_INGERSOLL_ROSS.
4. Updated the live knowledge docs (doc/knowledge/domain/*.org, renaming cir_process.org → cox_ingersoll_ross_process.org) and the component model (component_overview.org, ores.analytics.quant.puml) to match. Left closed sprint story/task docs (historical record) and not-yet-scheduled backlog captures referencing the old names untouched — out of this task's scope.
5. Full compass build and the ores.analytics.quant, ores.synthetic.api/core/service, and ores.qt test suites all green. db recreate confirms the renamed catalogue row (COX_INGERSOLL_ROSS) and constraints apply cleanly.

Manual QA scenarios (scaffolded via compass add test_scenario, run through the QA Validation Runner panel) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.

All four processes renamed throughout ores.analytics.quant (cir_process → cox_ingersoll_ross_process, ou_process → ornstein_uhlenbeck_process, gmm_process → gaussian_mixture_model_process, arithmetic_gmm_process → arithmetic_gaussian_mixture_model_process), including every downstream reference in ores.synthetic, ores.qt, and ores.sql. Stored process_type values renamed to match (cir=/=CIR → cox_ingersoll_ross=/=COX_INGERSOLL_ROSS, ou → ornstein_uhlenbeck), covering the yield-curve-process-types catalogue, SQL check constraints, and populate scripts. IrCurveEditor's engine combo now shows "Cox-Ingersoll-Ross" instead of the raw code, via the same code/label EngineInfo split FxSpotRateEditor already used. Live knowledge docs and the component model updated to match; closed sprint history and unscheduled backlog captures referencing the old names were left untouched (out of scope).

Full compass build rat (whole-repo build + test suite) green, SQL schema validation passed, and a fresh db recreate + Barclays-provisioning cycle confirmed the renamed catalogue row and constraints apply cleanly to real data. Manual QA scenario Verify CIR/OU/GMM process rename — CRUD, history, and both engine combos (IR curve's Cox-Ingersoll-Ross, FX's Ornstein-Uhlenbeck) — all steps PASSED.