feat: implement v2 3-tier architecture (mcpctl → mcplocal → mcpd)

- Rename local-proxy to mcplocal with HTTP server, LLM pipeline, mcpd discovery
- Add LLM pre-processing: token estimation, filter cache, metrics, Gemini CLI + DeepSeek providers
- Add mcpd auth (login/logout) and MCP proxy endpoints
- Update CLI: dual URLs (mcplocalUrl/mcpdUrl), auth commands, --direct flag
- Add tiered health monitoring, shell completions, e2e integration tests
- 57 test files, 597 tests passing

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

src/db/prisma/schema.prisma

@@ -10,13 +10,14 @@ datasource db {
 // ── Users ──
 
 model User {
-  id        String   @id @default(cuid())
-  email     String   @unique
-  name      String?
-  role      Role     @default(USER)
-  version   Int      @default(1)
-  createdAt DateTime @default(now())
-  updatedAt DateTime @updatedAt
+  id           String   @id @default(cuid())
+  email        String   @unique
+  name         String?
+  passwordHash String
+  role         Role     @default(USER)
+  version      Int      @default(1)
+  createdAt    DateTime @default(now())
+  updatedAt    DateTime @updatedAt
 
   sessions  Session[]
   auditLogs AuditLog[]