tools: remove file server registration

file_read and file_write removed from core; drop the file.Decl entry
from the dispatcher and the import.

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

internal/p9/server.go

@@ -38,7 +38,6 @@ import (
 	"ollie/pkg/skills"
 	"ollie/pkg/tools"
 	"ollie/pkg/tools/execute"
-	"ollie/pkg/tools/file"
 	"ollie/pkg/tools/reasoning"
 )
 
@@ -850,7 +849,6 @@ func (s *Server) createSession(args []string) error {
 
 	newDisp := tools.NewDispatcherFunc(map[string]func() tools.Server{
 		"execute":   execute.Decl(workdir),
-		"file":      file.Decl,
 		"reasoning": reasoning.Decl(),
 	})