Phase 3: Optimize & clean up — unified projects, account enhancements, new tenant fix

- Unify reserve_components + capital_projects into single projects model with
  full CRUD backend and new Projects page frontend
- Rewrite Capital Planning to read from unified projects/planning endpoint;
  add empty state directing users to Projects page when no planning items exist
- Add default designation to assessment groups with auto-set on first creation;
  units now require an assessment group (pre-populated with default)
- Add primary account designation (one per fund type) and balance adjustment
  via journal entries against equity offset accounts (3000/3100)
- Add computed investment fields (interest earned, maturity value, days remaining)
  with PostgreSQL date arithmetic fix for DATE - DATE integer result
- Restructure sidebar: investments in Accounts tab, Year-End under Reports,
  Planning section with Projects and Capital Planning
- Fix new tenant creation seeding unwanted default chart of accounts —
  new tenants now start with a blank slate

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/app.module.ts

@@ -20,6 +20,7 @@ import { InvestmentsModule } from './modules/investments/investments.module';
 import { CapitalProjectsModule } from './modules/capital-projects/capital-projects.module';
 import { ReportsModule } from './modules/reports/reports.module';
 import { AssessmentGroupsModule } from './modules/assessment-groups/assessment-groups.module';
+import { ProjectsModule } from './modules/projects/projects.module';
 
 @Module({
   imports: [
@@ -54,6 +55,7 @@ import { AssessmentGroupsModule } from './modules/assessment-groups/assessment-g
     CapitalProjectsModule,
     ReportsModule,
     AssessmentGroupsModule,
+    ProjectsModule,
   ],
   controllers: [AppController],
 })