server/server.go: 9P server in its own package

- server.New, server.Option, server.WithStrict, server.WithYolo
- main.go is now just wiring and CLI
- Clean package boundary: server/ = protocol, session/ = lifecycle, store/ = abstraction

main.go

@@ -14,6 +14,7 @@ import (
 	"9fans.net/go/plan9/client"
 	"ollie/pkg/env"
 	olog "ollie/pkg/log"
+	"olliesrv/server"
 )
 
 const serviceName = "ollie"
@@ -160,14 +161,14 @@ func runServer(sockPath, pidPath string) {
 	os.WriteFile(pidPath, []byte(fmt.Sprintf("%d", os.Getpid())), 0644) //nolint:errcheck
 
 	sink := olog.NewSink(os.Stdout, os.Stderr, olog.ParseLevel(os.Getenv("OLLIE_LOG"), olog.LevelWarn))
-	var srvOpts []ServerOption
+	var srvOpts []server.Option
 	if *strict {
-		srvOpts = append(srvOpts, WithStrict())
+		srvOpts = append(srvOpts, server.WithStrict())
 	}
 	if *yolo {
-		srvOpts = append(srvOpts, WithYolo())
+		srvOpts = append(srvOpts, server.WithYolo())
 	}
-	srv := New(sink, srvOpts...)
+	srv := server.New(sink, srvOpts...)
 
 	listener, err := net.Listen("unix", sockPath)
 	if err != nil {

server/server.go

@@ -1,6 +1,6 @@
 // 9P filesystem server for ollie sessions.
 // See doc comment below for filesystem layout.
-package main
+package server
 
 import (
 	"context"
@@ -80,14 +80,14 @@ type Server struct {
 	groups          map[string]map[string]bool // group → set of members
 }
 
-// ServerOption configures the 9P server.
-type ServerOption func(*Server)
+// Option configures the 9P server.
+type Option func(*Server)
 
-func WithStrict() ServerOption { return func(s *Server) { s.strict = true } }
-func WithYolo() ServerOption   { return func(s *Server) { s.yolo = true } }
+func WithStrict() Option { return func(s *Server) { s.strict = true } }
+func WithYolo() Option   { return func(s *Server) { s.yolo = true } }
 
 // New creates a new Server.
-func New(sink *olog.Sink, opts ...ServerOption) *Server {
+func New(sink *olog.Sink, opts ...Option) *Server {
 	memDir := defaultMemDir()
 	os.MkdirAll(memDir, 0755) //nolint:errcheck
 	transcriptDir := defaultTranscriptDir()