Initial commit: LlamaLink Go rewrite

Complete rewrite from Python/FastAPI to Go/Gin:
- Go backend: auth (API keys + bcrypt), llama.cpp subprocess manager,
  hot-swap multi-model, rate limiting, quota system, webhooks
- Vue 3 SPA admin panel (src/) with Tailwind CSS
- Deployment: Docker multi-stage, docker-compose, nginx, systemd
- GORM/SQLite models: ApiKey, Model, UsageLog, Quota, Webhook
- REST API: /api/v1/admin/* (keys, models, chat, usage, health)
- Embedded frontend via go:embed (build output at web/dist/)

Removed legacy Python artifacts (app/, tests/, pyproject.toml, etc.)

internal/config/config.go

@@ -0,0 +1,137 @@
+package config
+
+import (
+	"log/slog"
+	"os"
+	"strconv"
+	"time"
+)
+
+type Config struct {
+	// Server
+	LlamalinkEnv string
+	LlamalinkHost string
+	LlamalinkPort int
+
+	// Database
+	DatabaseURL         string
+	DatabaseMaxOpenConns int
+	DatabaseMaxIdleConns int
+	DatabaseConnMaxLifetime int // seconds
+
+	// Llama server management
+	ManageLlamaServer bool
+	LlamaServerBin    string
+	LlamaServerHost   string
+	LlamaServerPort   int
+	LlamaServerStartupTimeout int // seconds
+	LlamaServerStopTimeout    int // seconds
+	ModelSwapCooldown        int // seconds
+
+	// Rate limiting
+	RateLimitPerMinute int
+	RateLimitStorage   string // "memory" or "redis"
+
+	// Auth
+	AdminToken string
+
+	// Logging
+	LogLevel  string
+	LogFormat string // "json" or "text"
+}
+
+func Load() *Config {
+	c := &Config{
+		LlamalinkEnv:              getEnv("LLAMALINK_ENV", "development"),
+		LlamalinkHost:             getEnv("LLAMALINK_HOST", "0.0.0.0"),
+		LlamalinkPort:             intEnv("LLAMALINK_PORT", 8000),
+		DatabaseURL:               getEnv("DATABASE_URL", "sqlite:///./llamalink.db"),
+		DatabaseMaxOpenConns:      intEnv("DATABASE_MAX_OPEN_CONNS", 25),
+		DatabaseMaxIdleConns:       intEnv("DATABASE_MAX_IDLE_CONNS", 5),
+		DatabaseConnMaxLifetime:    intEnv("DATABASE_CONN_MAX_LIFETIME", 300),
+		ManageLlamaServer:         boolEnv("MANAGE_LLAMA_SERVER", true),
+		LlamaServerBin:            getEnv("LLAMA_SERVER_BIN", "/usr/local/bin/llama-server"),
+		LlamaServerHost:           getEnv("LLAMA_SERVER_HOST", "127.0.0.1"),
+		LlamaServerPort:           intEnv("LLAMA_SERVER_PORT", 8080),
+		LlamaServerStartupTimeout: intEnv("LLAMA_SERVER_STARTUP_TIMEOUT", 120),
+		LlamaServerStopTimeout:    intEnv("LLAMA_SERVER_STOP_TIMEOUT", 10),
+		ModelSwapCooldown:         intEnv("MODEL_SWAP_COOLDOWN", 2),
+		RateLimitPerMinute:        intEnv("RATE_LIMIT_PER_MINUTE", 60),
+		RateLimitStorage:          getEnv("RATE_LIMIT_STORAGE", "memory"),
+		AdminToken:                getEnv("ADMIN_TOKEN", "changeme"),
+		LogLevel:                  getEnv("LOG_LEVEL", "info"),
+		LogFormat:                 getEnv("LOG_FORMAT", "json"),
+	}
+	return c
+}
+
+func (c *Config) LlamaServerURL() string {
+	return "http://" + c.LlamaServerHost + ":" + strconv.Itoa(c.LlamaServerPort)
+}
+
+func (c *Config) LlamaServerStartupTimeoutDuration() time.Duration {
+	return time.Duration(c.LlamaServerStartupTimeout) * time.Second
+}
+
+func (c *Config) LlamaServerStopTimeoutDuration() time.Duration {
+	return time.Duration(c.LlamaServerStopTimeout) * time.Second
+}
+
+func (c *Config) ModelSwapCooldownDuration() time.Duration {
+	return time.Duration(c.ModelSwapCooldown) * time.Second
+}
+
+func (c *Config) Logger() *slog.Logger {
+	var level slog.Level
+	switch c.LogLevel {
+	case "debug":
+		level = slog.LevelDebug
+	case "warn":
+		level = slog.LevelWarn
+	case "error":
+		level = slog.LevelError
+	default:
+		level = slog.LevelInfo
+	}
+
+	opts := &slog.HandlerOptions{
+		Level: level,
+	}
+
+	var handler slog.Handler
+	if c.LogFormat == "text" {
+		handler = slog.NewTextHandler(os.Stdout, opts)
+	} else {
+		handler = slog.NewJSONHandler(os.Stdout, opts)
+	}
+
+	return slog.New(handler)
+}
+
+func getEnv(key, defaultValue string) string {
+	if v := os.Getenv(key); v != "" {
+		return v
+	}
+	return defaultValue
+}
+
+func intEnv(key string, defaultValue int) int {
+	if v := os.Getenv(key); v != "" {
+		if i, err := strconv.Atoi(v); err == nil {
+			return i
+		}
+	}
+	return defaultValue
+}
+
+func boolEnv(key string, defaultValue bool) bool {
+	if v := os.Getenv(key); v != "" {
+		if v == "true" || v == "1" || v == "yes" {
+			return true
+		}
+		if v == "false" || v == "0" || v == "no" {
+			return false
+		}
+	}
+	return defaultValue
+}