fix: bump bootstrap rust toolchain to 1.88

Update AWS bootstrap scripts to install Rust 1.88.0 so
cargo can build opencode-cloud 4.0.1 on EC2.

Author: pRizz

infra/aws/cloud-init/opencode-cloud-quick.yaml

@@ -88,7 +88,7 @@ write_files:
       if ! command -v cargo >/dev/null 2>&1; then
         log "opencode-cloud setup: install rust toolchain"
         curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
-          bash -s -- -y --profile minimal --default-toolchain 1.85.0
+          bash -s -- -y --profile minimal --default-toolchain 1.88.0
         log "opencode-cloud setup: rust toolchain installed"
       fi
 

infra/aws/cloudformation/opencode-cloud-quick.yaml

@@ -638,7 +638,7 @@ Resources:
                   if ! command -v cargo >/dev/null 2>&1; then
                     log "opencode-cloud setup: install rust toolchain"
                     curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
-                      bash -s -- -y --profile minimal --default-toolchain 1.85.0
+                      bash -s -- -y --profile minimal --default-toolchain 1.88.0
                     log "opencode-cloud setup: rust toolchain installed"
                   fi