feat(auth): phase 3 — replace Supabase GoTrue with bcryptjs+jose

Custom auth stack: bcryptjs password hashing (cost 10, GoTrue-compatible),
jose JWT session cookies (edge-safe, 8hr TTL), new API routes for
login/logout/reset/change-password, middleware rewritten to JWT-only
verification with no DB access. All 38 protected pages and API routes
migrated from supabase.auth.getUser() to getSession(). Supabase .from()
queries retained for Phase 4. lib/db/index.ts refactored to lazy Proxy
singleton to avoid module-level throw during Next.js build.

tsc: clean, build: clean, tests: 4/4 passed

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

app/api/dashboard/export/route.ts

@@ -2,15 +2,12 @@ export const dynamic = 'force-dynamic'
 
 import { NextRequest, NextResponse } from 'next/server'
 import { createClient } from '@/lib/supabase/server'
+import { getSession } from '@/lib/auth/get-session'
 import { rowsToCsv } from '@/lib/csv'
 
 export async function GET(request: NextRequest) {
-  const supabase = await createClient()
-  const { data: { user }, error: authError } = await supabase.auth.getUser()
-  if (authError || !user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
-
-  const { data: profile } = await supabase.from('users').select('role').eq('id', user.id).single()
-  if (!profile) return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
+  const session = await getSession()
+  if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
 
   const role = request.nextUrl.searchParams.get('role') ?? 'hse'
 
@@ -19,10 +16,12 @@ export async function GET(request: NextRequest) {
     management: ['management', 'admin'],
   }
 
-  if (!allowedRoles[role] || !allowedRoles[role].includes(profile.role)) {
+  if (!allowedRoles[role] || !allowedRoles[role].includes(session.role)) {
     return NextResponse.json({ error: 'Forbidden' }, { status: 403 })
   }
 
+  const supabase = await createClient()
+
   const { data: incidents } = await supabase
     .from('incidents')
     .select(`
@@ -64,7 +63,7 @@ export async function GET(request: NextRequest) {
 
   await supabase.rpc('write_audit_log', {
     p_table_name: 'incidents',
-    p_record_id: user.id,
+    p_record_id: session.sub,
     p_action: 'export_csv',
     p_new_value: { role, row_count: rows.length } as never,
   })