feat(18-02): REST API handlers for /api/v1/* endpoints

- Stats, keys, providers, scan, recon, dorks, config endpoints
- JSON response wrappers with proper tags for all entities
- Filtering, pagination, 404/204/202 status codes
- SSE hub stub (full impl in task 2)
- Resolved merge conflict in schema.sql
- 16 passing tests covering all endpoints

pkg/web/server.go

@@ -0,0 +1,34 @@
+// Package web implements the KeyHunter embedded web dashboard and REST API.
+package web
+
+import (
+	"github.com/salvacybersec/keyhunter/pkg/dorks"
+	"github.com/salvacybersec/keyhunter/pkg/engine"
+	"github.com/salvacybersec/keyhunter/pkg/providers"
+	"github.com/salvacybersec/keyhunter/pkg/recon"
+	"github.com/salvacybersec/keyhunter/pkg/storage"
+)
+
+// ServerConfig holds all dependencies injected into the web Server.
+type ServerConfig struct {
+	DB          *storage.DB
+	EncKey      []byte
+	Providers   *providers.Registry
+	Dorks       *dorks.Registry
+	ScanEngine  *engine.Engine
+	ReconEngine *recon.Engine
+}
+
+// Server is the central HTTP server holding all handler dependencies.
+type Server struct {
+	cfg ServerConfig
+	sse *SSEHub
+}
+
+// NewServer creates a Server with the given configuration.
+func NewServer(cfg ServerConfig) *Server {
+	return &Server{
+		cfg: cfg,
+		sse: NewSSEHub(),
+	}
+}