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/notifications/route.ts

@@ -2,17 +2,19 @@ export const dynamic = 'force-dynamic'
 
 import { NextRequest, NextResponse } from 'next/server'
 import { createClient } from '@/lib/supabase/server'
+import { getSession } from '@/lib/auth/get-session'
 
 export async function GET() {
+  const session = await getSession()
+  if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
   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: notifications, error } = await supabase
     .from('notifications_log')
     .select('id, title, link, incident_id, capa_id, sent_at, read_at')
     .eq('channel', 'in_app')
-    .eq('recipient_user_id', user.id)
+    .eq('recipient_user_id', session.sub)
     .order('sent_at', { ascending: false })
     .limit(20)
 
@@ -22,23 +24,24 @@ export async function GET() {
     .from('notifications_log')
     .select('id', { count: 'exact', head: true })
     .eq('channel', 'in_app')
-    .eq('recipient_user_id', user.id)
+    .eq('recipient_user_id', session.sub)
     .is('read_at', null)
 
   return NextResponse.json({ notifications: notifications ?? [], unread: count ?? 0 })
 }
 
 export async function POST(request: NextRequest) {
+  const session = await getSession()
+  if (!session) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
+
   const supabase = await createClient()
-  const { data: { user }, error: authError } = await supabase.auth.getUser()
-  if (authError || !user) return NextResponse.json({ error: 'Unauthorized' }, { status: 401 })
 
   const body: { ids?: string[]; all?: boolean } = await request.json().catch(() => ({}))
 
   let query = supabase
     .from('notifications_log')
     .update({ read_at: new Date().toISOString() })
-    .eq('recipient_user_id', user.id)
+    .eq('recipient_user_id', session.sub)
     .is('read_at', null)
 
   if (!body.all) {