Docs: README for 0.0.4 (cross-region install works, UI updates, filename)

README catches up to where the code is:

- The "cross-region install is a known limitation" section is gone. We
  route through sceAppInstUtilAppInstallPkg now, verified end-to-end on
  Dead Island 2 (01.000.001 -> 01.000.011, including the shared-storage
  case where the patch lives under a master title id).
- A Web UI section documents the filter chips (Updatable default,
  Updating separate bucket, All on the right) and Update all.
- Deploy section notes the new filename shape (patchdl_<version>.elf)
  so Payload Manager can parse the version out of it.

deploy_ps5.sh follows: UP_NAME is now patchdl_${VERSION}.elf to match
the released asset naming.

scripts/deploy_ps5.sh

@@ -19,7 +19,7 @@ VERSION=$(sed -n 's/.*PATCHDL_VERSION[^"]*"\([^"]*\)".*/\1/p' "$ROOT_DIR/src/pat
 SRC_ELF="$ROOT_DIR/patchdl-ps5.elf"
 [ -f "$SRC_ELF" ] || { echo "build first: $SRC_ELF missing" >&2; exit 1; }
 
-UP_NAME="patchdl-ps5-v${VERSION}.elf"
+UP_NAME="patchdl_${VERSION}.elf"
 TMP_ELF="$ROOT_DIR/$UP_NAME"
 cp "$SRC_ELF" "$TMP_ELF"