docs(desktop): add architecture migration issue block

.agents/session-log.md

@@ -389,5 +389,7 @@
 - 2026-04-10: Completed issue #342 primary workbench ownership. The renderer now marks workbench-heavy surfaces explicitly and collapses the outer support lane plus internal two-column workbench grids earlier, so `Runs`, `Compare`, `Candidates`, `Run Detail`, and `Paper Ops` stop holding two side rails at the same laptop-width breakpoint. Validation passed with `node --check desktop/renderer/app.js`, `npm run smoke:fallback`, and `npm run smoke:real-path`.
 - 2026-04-10: Started issue #346 to harden `desktop-smoke` result persistence after CI repeatedly failed with raw `ENOENT` on missing `result.json` in a planning-only PR. The slice is limited to `desktop/main.js`, `desktop/scripts/smoke.js`, and `.agents` continuity so smoke emits structured failures instead of crashing when Electron exits too early.
 - 2026-04-10: Added the desktop layout regression remediation block after reviewing the post-merge desktop state in real screenshots. Opened issues #342, #343, and #344 to target empty-pane collapse, stronger active-surface focus and context containment, and better runs-family density plus right-rail space budgeting without reopening core or `research_ui` scope.
+<<<<<<< HEAD
+- 2026-04-10: Added the Desktop architecture migration block after accepting the ADR direction for the new shell foundation. Opened issues #350, #354, #353, #355, #352, #359, #351, #357, #358, and #356 so the migration is tracked as real slices rather than dozens of micro-backlog items.
 - 2026-04-10: Started the desktop shared contracts foundation slice on branch `codex/desktop-shared-workspace-contract`. The goal is to establish the first real shared Desktop contract layer before opening the larger `desktop-typescript-base` slice, limited to workspace, runtime/snapshot, and smoke boundaries.
 - 2026-04-10: Completed the desktop shared contracts foundation slice. Added `desktop/shared` contracts for IPC channels, envelopes, workspace state, runtime state, snapshot status, and smoke results, and connected them back into `desktop/main.js`, `desktop/preload.js`, `desktop/renderer/app.js`, and `desktop/scripts/smoke.js` via narrow JSDoc typing only, without changing desktop behavior.

.agents/tasks/issue-350-desktop-target-architecture-and-shared-contract-guardrails.md

@@ -0,0 +1,14 @@
+# Issue #350 — Desktop Target Architecture and Shared Contract Guardrails
+
+## Goal
+Lock the migration direction and guardrails for the Desktop architecture so later slices do not reopen stack, boundary, or target-state debates.
+
+## Expected deliverable
+- accepted ADR
+- explicit transition rules
+- shared-contract-first ordering
+
+## Done when
+- the architecture direction is fixed
+- `research_ui` is explicitly transitional
+- the next slice can move into TypeScript base real cleanly

.agents/tasks/issue-351-migrate-run-detail-and-artifacts.md

@@ -0,0 +1,11 @@
+# Issue #351 — Migrate Run Detail and Artifacts
+
+## Goal
+Move run-level evidence review into the new renderer stack after core workstation surfaces.
+
+## Expected deliverable
+- migrated Run Detail
+- migrated Artifacts
+
+## Done when
+- evidence review no longer depends on the legacy shell path

.agents/tasks/issue-352-minimal-react-shell-frame.md

@@ -0,0 +1,14 @@
+# Issue #352 — Minimal React Shell Frame
+
+## Goal
+Introduce the new shell frame without migrating all surfaces at once.
+
+## Expected deliverable
+- shell layout
+- sidebar
+- topbar
+- support lane frame
+- focused surface tabs
+
+## Done when
+- the React shell exists and hosts transitional surfaces without uncontrolled drift

.agents/tasks/issue-353-modularize-desktop-main-process.md

@@ -0,0 +1,12 @@
+# Issue #353 — Modularize Desktop Main Process
+
+## Goal
+Split the Electron main process by responsibility after the TypeScript base exists.
+
+## Expected deliverable
+- thin `main.js`
+- typed modules for bootstrap, window, workspace, IPC, and smoke support
+
+## Done when
+- responsibilities are separated into coherent modules
+- runtime behavior stays unchanged

.agents/tasks/issue-354-typescript-base-across-desktop.md

@@ -0,0 +1,15 @@
+# Issue #354 — TypeScript Base Across Desktop
+
+## Goal
+Establish the real TypeScript base for `desktop/` without changing runtime behavior.
+
+## Expected deliverable
+- `tsconfig.json`
+- `types/global.d.ts`
+- `typecheck`
+- native use of `desktop/shared`
+
+## Done when
+- current Desktop JS entrypoints pass typecheck
+- smoke remains green
+- no functional change is introduced

.agents/tasks/issue-355-typed-preload-bridge-and-stable-ipc-surface.md

@@ -0,0 +1,13 @@
+# Issue #355 — Typed Preload Bridge and Stable IPC Surface
+
+## Goal
+Turn preload into the stable typed bridge between main and renderer.
+
+## Expected deliverable
+- typed preload API
+- typed event subscriptions
+- stable Desktop surface exposed to the renderer
+
+## Done when
+- preload is fully typed
+- renderer depends on a clear bridge contract

.agents/tasks/issue-356-retire-legacy-shell-renderer.md

@@ -0,0 +1,11 @@
+# Issue #356 — Retire Legacy Shell Renderer
+
+## Goal
+Remove the transitional shell path once the new architecture owns Desktop end to end.
+
+## Expected deliverable
+- legacy shell retirement
+- removal of transitional duplication
+
+## Done when
+- the new Desktop architecture is the only maintained shell path

.agents/tasks/issue-357-migrate-paper-ops-system-experiments.md

@@ -0,0 +1,12 @@
+# Issue #357 — Migrate Paper Ops, System, and Experiments
+
+## Goal
+Move the remaining operational Desktop surfaces into the new renderer architecture.
+
+## Expected deliverable
+- migrated Paper Ops
+- migrated System
+- migrated Experiments
+
+## Done when
+- those surfaces are owned by the new shell architecture

.agents/tasks/issue-358-decide-and-resolve-launch-target-state.md

@@ -0,0 +1,11 @@
+# Issue #358 — Decide and Resolve Launch Target-State
+
+## Goal
+Make Launch explicit as product and architecture target-state instead of preserving embedded continuity by inertia.
+
+## Expected deliverable
+- explicit Launch target-state decision
+- implementation aligned with the new shell architecture
+
+## Done when
+- Launch is no longer architecturally ambiguous

.agents/tasks/issue-359-migrate-core-workstation-surfaces.md

@@ -0,0 +1,11 @@
+# Issue #359 — Migrate Core Workstation Surfaces
+
+## Goal
+Move Runs, Compare, and Candidates into the new renderer stack.
+
+## Expected deliverable
+- migrated core decision surfaces
+- preserved selection and compare continuity
+
+## Done when
+- these surfaces no longer depend on the legacy shell path

.agents/tasks/issue-block-desktop-architecture-migration.md

@@ -0,0 +1,20 @@
+# Desktop Architecture Migration Block
+
+This block groups the real migration slices for the QuantLab Desktop architecture transition.
+
+Order:
+
+1. `#350` Desktop target architecture and shared contract guardrails
+2. `#354` TypeScript base real across main, preload, shared, and renderer
+3. `#353` Modularize the desktop main process
+4. `#355` Complete typed preload bridge and stable Desktop IPC surface
+5. `#352` Establish the minimal React shell frame
+6. `#359` Migrate core workstation surfaces: Runs, Compare, Candidates
+7. `#351` Migrate Run Detail and Artifacts
+8. `#357` Migrate Paper Ops, System, and Experiments
+9. `#358` Decide and resolve Launch target-state
+10. `#356` Retire the legacy shell renderer
+
+Principle:
+- one real slice = one issue = one branch = one PR
+- micro-cuts stay inside the slice branch and do not become backlog units