profile picture image cache

coding from a plane so this is helping alot with PFPs

src/error.rs

@@ -1,8 +1,10 @@
-use std::fmt;
+use std::{fmt, io};
 
 #[derive(Debug)]
 pub enum Error {
     NoActiveSubscription,
+    LoadFailed,
+    Io(io::Error),
     Nostr(enostr::Error),
     Ndb(nostrdb::Error),
     Image(image::error::ImageError),
@@ -15,10 +17,14 @@ impl fmt::Display for Error {
             Self::NoActiveSubscription => {
                 write!(f, "subscription not active in timeline")
             }
+            Self::LoadFailed => {
+                write!(f, "load failed")
+            }
             Self::Nostr(e) => write!(f, "{e}"),
             Self::Ndb(e) => write!(f, "{e}"),
             Self::Image(e) => write!(f, "{e}"),
             Self::Generic(e) => write!(f, "{e}"),
+            Self::Io(e) => write!(f, "{e}"),
         }
     }
 }
@@ -46,3 +52,9 @@ impl From<enostr::Error> for Error {
         Error::Nostr(err)
     }
 }
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Self {
+        Error::Io(err)
+    }
+}