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/modules/assessment-groups/assessment-groups.controller.ts

@@ -16,6 +16,9 @@ export class AssessmentGroupsController {
   @Get('summary')
   getSummary() { return this.service.getSummary(); }
 
+  @Get('default')
+  getDefault() { return this.service.getDefault(); }
+
   @Get(':id')
   findOne(@Param('id') id: string) { return this.service.findOne(id); }
 
@@ -24,4 +27,7 @@ export class AssessmentGroupsController {
 
   @Put(':id')
   update(@Param('id') id: string, @Body() dto: any) { return this.service.update(id, dto); }
+
+  @Put(':id/set-default')
+  setDefault(@Param('id') id: string) { return this.service.setDefault(id); }
 }