Fix terminal resize handling and cached updates

install.sh

@@ -10,6 +10,7 @@ prefix="${PREFIX:-$HOME/.local}"
 from_current=0
 start_server=1
 force_config=0
+update_cache="${DOSH_UPDATE_CACHE:-$HOME/.cache/dosh/source}"
 
 usage() {
   cat <<'EOF'
@@ -22,11 +23,14 @@ Options:
   --dosh-host HOST  UDP host for Dosh packets when different from SSH target
   --port PORT       Dosh UDP port; default 50000
   --prefix DIR      Install prefix; default ~/.local
+  --update-cache DIR
+                  Persistent source checkout for incremental updates
   --no-start        Install server but do not start it
   --force-config    Rewrite existing ~/.config/dosh/*.toml files
 
 Environment alternatives:
-  DOSH_REPO, DOSH_ROLE, DOSH_SERVER, DOSH_HOST, DOSH_PORT, PREFIX
+  DOSH_REPO, DOSH_ROLE, DOSH_SERVER, DOSH_HOST, DOSH_PORT, PREFIX,
+  DOSH_UPDATE_CACHE
 EOF
 }
 
@@ -55,6 +59,10 @@ while [ "$#" -gt 0 ]; do
       prefix="$2"
       shift
       ;;
+    --update-cache)
+      update_cache="$2"
+      shift
+      ;;
     --from-current)
       from_current=1
       ;;
@@ -119,15 +127,28 @@ else
     echo "DOSH_REPO or --repo is required when running the installer from curl" >&2
     exit 2
   fi
+  case "$update_cache" in
+    ""|"/"|"$HOME"|"$HOME/"|"$HOME/.cache")
+      echo "refusing unsafe update cache path: $update_cache" >&2
+      exit 2
+      ;;
+  esac
   need git
-  tmpdir="$(mktemp -d)"
-  git clone --depth 1 "$repo" "$tmpdir/dosh" >/dev/null
-  src_dir="$tmpdir/dosh"
+  mkdir -p "$(dirname "$update_cache")"
+  if [ -d "$update_cache/.git" ]; then
+    git -C "$update_cache" remote set-url origin "$repo"
+    git -C "$update_cache" fetch --depth 1 origin main
+    git -C "$update_cache" checkout -q -B main FETCH_HEAD
+  else
+    rm -rf "$update_cache"
+    git clone --depth 1 --branch main "$repo" "$update_cache" >/dev/null
+  fi
+  src_dir="$update_cache"
 fi
 
 cd "$src_dir"
 if [ "$role" = "client" ]; then
-  cargo build --release --bin dosh-client --bin dosh-bench
+  cargo build --release --bin dosh-client
 else
   cargo build --release
 fi