Add Postgres storage layer and CRUD handlers

Add the store package (pgx-backed repository) with CRUD for the core resources
the compiler needs: fabrics, zones, address groups, portgroups, devices,
bindings, rules, policies. Every mutation bumps a global config generation.
Wire real JSON CRUD handlers with token auth, source/dest grammar validation on
rule create, and the agent status-report endpoint. Migration 0001 verified
against Postgres 17.

internal/server/server.go

@@ -14,6 +14,7 @@ import (
 	"github.com/go-chi/chi/v5/middleware"
 
 	"git.unkin.net/unkin/tomswallapi/internal/database"
+	"git.unkin.net/unkin/tomswallapi/internal/store"
 )
 
 // Options configures a Server.
@@ -27,6 +28,7 @@ type Options struct {
 // Server serves the tomswallapi HTTP API.
 type Server struct {
 	db         *database.DB
+	store      *store.Store
 	writeToken string
 	agentToken string
 	version    string
@@ -36,6 +38,7 @@ type Server struct {
 func New(o Options) *Server {
 	return &Server{
 		db:         o.DB,
+		store:      store.New(o.DB.Pool),
 		writeToken: o.WriteToken,
 		agentToken: o.AgentToken,
 		version:    o.Version,