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>

frontend/src/components/layout/Sidebar.tsx

@@ -10,10 +10,8 @@ import {
   IconReportAnalytics,
   IconChartSankey,
   IconShieldCheck,
-  IconPigMoney,
   IconBuildingBank,
   IconUsers,
-  IconFileText,
   IconSettings,
   IconCrown,
   IconCategory,
@@ -31,7 +29,6 @@ const navSections = [
     items: [
       { label: 'Accounts', icon: IconListDetails, path: '/accounts' },
       { label: 'Budgets', icon: IconReportAnalytics, path: '/budgets/2026' },
-      { label: 'Investments', icon: IconPigMoney, path: '/investments' },
     ],
   },
   {
@@ -52,8 +49,8 @@ const navSections = [
   {
     label: 'Planning',
     items: [
-      { label: 'Capital Projects', icon: IconBuildingBank, path: '/capital-projects' },
-      { label: 'Reserves', icon: IconShieldCheck, path: '/reserves' },
+      { label: 'Projects', icon: IconShieldCheck, path: '/projects' },
+      { label: 'Capital Planning', icon: IconBuildingBank, path: '/capital-projects' },
       { label: 'Vendors', icon: IconUsers, path: '/vendors' },
     ],
   },
@@ -70,6 +67,7 @@ const navSections = [
           { label: 'Budget vs Actual', path: '/reports/budget-vs-actual' },
           { label: 'Aging Report', path: '/reports/aging' },
           { label: 'Sankey Diagram', path: '/reports/sankey' },
+          { label: 'Year-End', path: '/reports/year-end' },
         ],
       },
     ],
@@ -77,7 +75,6 @@ const navSections = [
   {
     label: 'Admin',
     items: [
-      { label: 'Year-End', icon: IconFileText, path: '/year-end' },
       { label: 'Settings', icon: IconSettings, path: '/settings' },
     ],
   },