9p: remove file and reasoning server registrations; session tmpdir init

- Remove file.Decl and reasoning.Decl from dispatcher
- go mod tidy: drop go-udiff dependency
- Initialize /tmp/ollie/$sessID on session create (rm -rf + mkdir)
- Rename /tmp/ollie/$oldID -> $newID on session rename

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

go.mod

@@ -7,9 +7,6 @@ require (
 	ollie v0.0.0-00010101000000-000000000000
 )
 
-require (
-	github.com/aymanbagabas/go-udiff v0.4.1 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
-)
+require gopkg.in/yaml.v3 v3.0.1 // indirect
 
 replace ollie => ../core

go.sum

@@ -2,8 +2,6 @@
 9fans.net/go v0.0.7/go.mod h1:Rxvbbc1e+1TyGMjAvLthGTyO97t+6JMQ6ly+Lcs9Uf0=
 dmitri.shuralyov.com/gpu/mtl v0.0.0-20201218220906-28db891af037/go.mod h1:H6x//7gZCb22OMCxBHrMx7a5I7Hp++hsVxbQ4BYO7hU=
 github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
-github.com/aymanbagabas/go-udiff v0.4.1 h1:OEIrQ8maEeDBXQDoGCbbTTXYJMYRCRO1fnodZ12Gv5o=
-github.com/aymanbagabas/go-udiff v0.4.1/go.mod h1:0L9PGwj20lrtmEMeyw4WKJ/TMyDtvAoK9bf2u/mNo3w=
 github.com/go-gl/glfw/v3.3/glfw v0.0.0-20200222043503-6f7a984d4dc4/go.mod h1:tQ2UAYgL5IevRw8kRxooKSPJfGvJ9fJQFa0TUsXzTg8=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=

internal/p9/server.go

@@ -50,8 +50,6 @@ import (
 	"ollie/pkg/skills"
 	"ollie/pkg/tools"
 	"ollie/pkg/tools/execute"
-	"ollie/pkg/tools/file"
-	"ollie/pkg/tools/reasoning"
 )
 
 const (
@@ -972,6 +970,13 @@ func (s *Server) renameSession(oldID, newID string) error {
 		c.mu.Unlock()
 	}
 
+	// Rename the session tmpdir so isread markers remain valid.
+	oldTemp := "/tmp/ollie/" + oldID
+	newTemp := "/tmp/ollie/" + newID
+	if _, err := os.Stat(oldTemp); err == nil {
+		os.Rename(oldTemp, newTemp) //nolint:errcheck
+	}
+
 	sess.appendChat([]byte(fmt.Sprintf("(session renamed: %s -> %s)\n", oldID, newID)))
 	fmt.Fprintf(os.Stderr, "olliesrv: renamed session %s -> %s\n", oldID, newID)
 	return nil
@@ -1308,8 +1313,6 @@ func (s *Server) createSession(args []string) error {
 
 	newDisp := tools.NewDispatcherFunc(map[string]func() tools.Server{
 		"execute":   execute.Decl(cwd),
-		"file":      file.Decl(cwd),
-		"reasoning": reasoning.Decl(),
 	})
 
 	sessID := name
@@ -1324,6 +1327,11 @@ func (s *Server) createSession(args []string) error {
 		return fmt.Errorf("session already exists: %s", sessID)
 	}
 
+	// Initialize clean tmpdir for this session.
+	sessTemp := "/tmp/ollie/" + sessID
+	os.RemoveAll(sessTemp)          //nolint:errcheck
+	os.MkdirAll(sessTemp, 0700)     //nolint:errcheck
+
 	env := agent.BuildAgentEnv(cfg, newDisp(), cwd)
 
 	// Inject per-session env vars into the execute server.