feat: V2 microservices stack — backend services, gateway, JWT auth

Add full V2 architecture: identity, content, studio (.NET 10) and file,
render, notification, gateway (Go) services with vendored deps, plus DB
migrations, event/API contracts, and an init-db script.

Wire the Next.js frontend to the gateway: server-side JWT auth routes
(login/register/refresh/logout/me), gateway fetch helper, and session/
cookie/jwt helpers under src/lib.

Containerize the stack via docker-compose.v2.yml and per-service
Dockerfiles. Base images resolve through a Nexus mirror (Docker Hub) and
MCR directly; npm/NuGet pull from Nexus groups. Self-host fonts via
next/font/local to avoid Google Fonts (geo-blocked).

Add CI workflow and ignore .env.v2, *.stackdump, and .NET bin/obj.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

services/notification/vendor/github.com/jackc/pgservicefile/LICENSE

@@ -0,0 +1,22 @@
+Copyright (c) 2020 Jack Christensen
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

services/notification/vendor/github.com/jackc/pgservicefile/README.md

@@ -0,0 +1,7 @@
+[![Go Reference](https://pkg.go.dev/badge/github.com/jackc/pgservicefile.svg)](https://pkg.go.dev/github.com/jackc/pgservicefile)
+[![Build Status](https://github.com/jackc/pgservicefile/actions/workflows/ci.yml/badge.svg)](https://github.com/jackc/pgservicefile/actions/workflows/ci.yml)
+
+
+# pgservicefile
+
+Package pgservicefile is a parser for PostgreSQL service files (e.g. `.pg_service.conf`).

services/notification/vendor/github.com/jackc/pgservicefile/pgservicefile.go

@@ -0,0 +1,81 @@
+// Package pgservicefile is a parser for PostgreSQL service files (e.g. .pg_service.conf).
+package pgservicefile
+
+import (
+	"bufio"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+)
+
+type Service struct {
+	Name     string
+	Settings map[string]string
+}
+
+type Servicefile struct {
+	Services       []*Service
+	servicesByName map[string]*Service
+}
+
+// GetService returns the named service.
+func (sf *Servicefile) GetService(name string) (*Service, error) {
+	service, present := sf.servicesByName[name]
+	if !present {
+		return nil, errors.New("not found")
+	}
+	return service, nil
+}
+
+// ReadServicefile reads the file at path and parses it into a Servicefile.
+func ReadServicefile(path string) (*Servicefile, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	return ParseServicefile(f)
+}
+
+// ParseServicefile reads r and parses it into a Servicefile.
+func ParseServicefile(r io.Reader) (*Servicefile, error) {
+	servicefile := &Servicefile{}
+
+	var service *Service
+	scanner := bufio.NewScanner(r)
+	lineNum := 0
+	for scanner.Scan() {
+		lineNum += 1
+		line := scanner.Text()
+		line = strings.TrimSpace(line)
+
+		if line == "" || strings.HasPrefix(line, "#") {
+			// ignore comments and empty lines
+		} else if strings.HasPrefix(line, "[") && strings.HasSuffix(line, "]") {
+			service = &Service{Name: line[1 : len(line)-1], Settings: make(map[string]string)}
+			servicefile.Services = append(servicefile.Services, service)
+		} else if service != nil {
+			parts := strings.SplitN(line, "=", 2)
+			if len(parts) != 2 {
+				return nil, fmt.Errorf("unable to parse line %d", lineNum)
+			}
+
+			key := strings.TrimSpace(parts[0])
+			value := strings.TrimSpace(parts[1])
+
+			service.Settings[key] = value
+		} else {
+			return nil, fmt.Errorf("line %d is not in a section", lineNum)
+		}
+	}
+
+	servicefile.servicesByName = make(map[string]*Service, len(servicefile.Services))
+	for _, service := range servicefile.Services {
+		servicefile.servicesByName[service.Name] = service
+	}
+
+	return servicefile, scanner.Err()
+}