feat(FN-2991): merge fusion/fn-2991

Commits merged:
- fix(FN-2991): align failed research status badge semantics
- feat(FN-2991): add research dashboard view and navigation entry
- fix(FN-2991): complete Step 8 — resolve lint and typecheck gates
- test(FN-2991): address review feedback for Step 7
- test(FN-2991): complete Step 7 — add research store and route tests
- feat(FN-2991): complete Step 6 — add research client API helpers
- feat(FN-2991): complete Step 5 — add research REST routes
- feat(FN-2991): complete Step 4 — wire research store into core exports
- feat(FN-2991): complete Step 3 — implement research store
- feat(FN-2991): complete Step 2 — add research schema and migration
- feat(FN-2991): complete Step 1 — add research domain types

Files changed:
packages/core/src/__tests__/db.test.ts             |  26 +-
 packages/core/src/__tests__/insight-store.test.ts  |   8 +-
 packages/core/src/__tests__/mission-store.test.ts  |   2 +-
 packages/core/src/__tests__/research-store.test.ts | 118 +++++++
 packages/core/src/__tests__/roadmap-store.test.ts  |   2 +-
 packages/core/src/__tests__/run-audit.test.ts      |   2 +-
 packages/core/src/__tests__/task-documents.test.ts |   2 +-
 packages/core/src/db.ts                            |  82 ++++-
 packages/core/src/index.ts                         |  30 ++
 packages/core/src/research-store.ts                | 377 +++++++++++++++++++++
 packages/core/src/research-types.ts                | 162 +++++++++
 packages/core/src/store.ts                         |  14 +
 packages/dashboard/app/App.tsx                     |  12 +
 .../app/api/__tests__/research-api.test.ts         | 120 +++++++
 packages/dashboard/app/api/legacy.ts               | 132 +++++++-
 packages/dashboard/app/components/Header.tsx       |  23 +-
 packages/dashboard/app/components/MobileNavBar.tsx |  16 +-
 packages/dashboard/app/components/ResearchView.css | 110 ++++++
 packages/dashboard/app/components/ResearchView.tsx | 145 ++++++++
 .../app/components/__tests__/Header.test.tsx       |   4 +-
 .../app/components/__tests__/ResearchView.test.tsx | 170 ++++++++++
 packages/dashboard/app/hooks/useViewState.ts       |   3 +-
 packages/dashboard/src/research-routes.ts          | 223 ++++++++++++
 .../src/routes/register-integrated-routers.ts      |   2 +
 24 files changed, 1751 insertions(+), 34 deletions(-)

Fusion-Task-Id: FN-2991

packages/core/src/index.ts

@@ -575,6 +575,36 @@ export type {
   InsightRunListOptions,
   InsightStoreEvents,
 } from "./insight-types.js";
+
+// ── Research System ───────────────────────────────────────────────────────
+
+export { ResearchStore } from "./research-store.js";
+export {
+  RESEARCH_RUN_STATUSES,
+  RESEARCH_SOURCE_STATUSES,
+  RESEARCH_EXPORT_FORMATS,
+  RESEARCH_SOURCE_TYPES,
+  RESEARCH_EVENT_TYPES,
+} from "./research-types.js";
+export type {
+  ResearchRunStatus,
+  ResearchSourceStatus,
+  ResearchExportFormat,
+  ResearchSourceType,
+  ResearchEventType,
+  ResearchSource,
+  ResearchEvent,
+  ResearchFinding,
+  ResearchResult,
+  ResearchTokenUsage,
+  ResearchRun,
+  ResearchExport,
+  ResearchRunCreateInput,
+  ResearchRunUpdateInput,
+  ResearchRunListOptions,
+  ResearchStoreEvents,
+} from "./research-types.js";
+
 export { TodoStore } from "./todo-store.js";
 export type { TodoStoreEvents } from "./todo-store.js";