release: add aarch64 (linux arm64) binary + .pdm to download/mirror

- Download pmm-aarch64 + pmm-0.3.6-linux-aarch64.pdm into web/download, and the
  .pdm into web/mirror/packages/pmm/.
- Add the linux/aarch64 0.3.6 variant to pmm.json (with correct sha256).
- Sync web/download/install.sh to the arch-aware version.

web/download/install.sh

@@ -23,11 +23,12 @@ case "$ARCH" in
   *) echo "pmm: 不支持的架构 $ARCH"; exit 1 ;;
 esac
 
-# ---- 下载 pmm（release 资产名为 pmm）----
-URL="https://github.com/$REPO/releases/download/v$VER/pmm"
-if [ "$arch" != "amd64" ]; then
-  echo "pmm: 注意：官方发布目前只提供 amd64 资产，$os/$arch 可能 404"
-fi
+# ---- 下载 pmm（按架构选 release 资产名）----
+case "$arch" in
+  amd64) ASSET="pmm" ;;
+  arm64) ASSET="pmm-aarch64" ;;
+esac
+URL="https://github.com/$REPO/releases/download/v$VER/$ASSET"
 echo "pmm: 下载 v$VER ($os/$arch) ..."
 TMP="$(mktemp)"
 # --progress-bar shows a live download progress line (tty only)

web/mirror/packages/pmm.json

@@ -400,6 +400,15 @@
             "url": "https://pmm.parlz.com/mirror/packages/pmm/0.3.6-linux-amd64.pdm",
             "sha256": "06f988dd8523243c9d4117805ef8d23a03b1365e0018d7d6d8d92c6ed9db1a40",
             "description": "PMM v0.3.6"
+        },
+        {
+            "version": "0.3.6",
+            "os": "linux",
+            "arch": "aarch64",
+            "file": "0.3.6-linux-aarch64.pdm",
+            "url": "https://pmm.parlz.com/mirror/packages/pmm/0.3.6-linux-aarch64.pdm",
+            "sha256": "5f1d28759e25d143df822a8851193a49fef6152cadcec16bbac3607dae8bf22c",
+            "description": "PMM v0.3.6 (aarch64)"
         }
     ]
 }