Enhance cloud storage handling and configuration documentation

- Updated `ssr.conf.example` to clarify the usage of `SSR_CLOUD_PATH` for custom cloud providers, including examples for handling multiple folders.
- Introduced `ssr::cloud::resolve_storage_pattern` function in `lib/cloud.sh` to improve directory resolution for cloud storage providers, ensuring proper handling of multiple matches.
- Refactored `ssr::cloud::resolve_dir` to utilize the new storage resolution function, enhancing error handling and user feedback for cloud directory detection.

lib/cloud.sh

@@ -2,6 +2,66 @@
 # lib/cloud.sh — cloud storage provider abstraction.
 # Resolves SSR_CLOUD_DIR based on SSR_CLOUD_PROVIDER from config.
 
+# Echo one directory under ~/Library/CloudStorage matching find -name "$1".
+# $2 = label for errors (e.g. OneDrive). $3 = optional fallback dir if zero matches.
+# If several folders match (e.g. personal + work OneDrive), SSR_CLOUD_PATH must
+# be set to the absolute path of the chosen root (same as one of the matches);
+# otherwise we abort with a list of candidates. Tilde in SSR_CLOUD_PATH is expanded.
+ssr::cloud::resolve_storage_pattern() {
+    local pattern="$1" label="$2" zero_fallback="${3:-}"
+    local cs="$HOME/Library/CloudStorage"
+    local custom="${SSR_CLOUD_PATH:-}"
+    case "$custom" in
+        '~' | '~'/*) custom="${custom/#\~/$HOME}" ;;
+    esac
+
+    local matches=()
+    local d
+    if [[ -d "$cs" ]]; then
+        while IFS= read -r d; do
+            [[ -n "$d" && -d "$d" ]] && matches+=("$d")
+        done < <(find "$cs" -maxdepth 1 -type d -name "$pattern" 2>/dev/null | LC_ALL=C sort -u)
+    fi
+
+    local n="${#matches[@]}"
+    if [[ "$n" -eq 0 ]]; then
+        if [[ -n "$zero_fallback" && -d "$zero_fallback" ]]; then
+            printf '%s\n' "$zero_fallback"
+            return 0
+        fi
+        ssr::die "$label folder not found under ~/Library/CloudStorage"
+    fi
+    if [[ "$n" -eq 1 ]]; then
+        printf '%s\n' "${matches[0]}"
+        return 0
+    fi
+
+    if [[ -z "$custom" ]]; then
+        ssr::err "Multiple $label folders found; set SSR_CLOUD_PATH in ssr.conf to the root you want (absolute path), or use SSR_CLOUD_PROVIDER=custom."
+        for d in "${matches[@]}"; do ssr::err "  $d"; done
+        exit 1
+    fi
+
+    ssr::validate_path "$custom"
+    [[ -d "$custom" ]] || ssr::die "SSR_CLOUD_PATH is not a directory: $custom"
+
+    local abs_c abs_m picked=""
+    abs_c="$(cd "$custom" && pwd -P)" || ssr::die "SSR_CLOUD_PATH not accessible: $custom"
+    for d in "${matches[@]}"; do
+        abs_m="$(cd "$d" && pwd -P)" || continue
+        if [[ "$abs_m" == "$abs_c" ]]; then
+            picked="$d"
+            break
+        fi
+    done
+    if [[ -z "$picked" ]]; then
+        ssr::err "SSR_CLOUD_PATH=$custom is not one of the detected $label roots:"
+        for d in "${matches[@]}"; do ssr::err "  $d"; done
+        exit 1
+    fi
+    printf '%s\n' "$picked"
+}
+
 ssr::cloud::resolve_dir() {
     local provider="${SSR_CLOUD_PROVIDER:-icloud}" custom="${SSR_CLOUD_PATH:-}"
 
@@ -10,23 +70,25 @@ ssr::cloud::resolve_dir() {
             printf '%s\n' "$HOME/Library/Mobile Documents/com~apple~CloudDocs"
             ;;
         dropbox)
-            if [[ -d "$HOME/Library/CloudStorage" ]]; then
-                find "$HOME/Library/CloudStorage" -maxdepth 1 -type d -name 'Dropbox*' -print -quit 2>/dev/null \
-                    || printf '%s\n' "$HOME/Dropbox"
-            else
+            if [[ ! -d "$HOME/Library/CloudStorage" ]]; then
+                [[ -d "$HOME/Dropbox" ]] || ssr::die "Dropbox not found (no ~/Library/CloudStorage and no ~/Dropbox)."
                 printf '%s\n' "$HOME/Dropbox"
+                return 0
             fi
+            ssr::cloud::resolve_storage_pattern 'Dropbox*' 'Dropbox' "$HOME/Dropbox"
             ;;
         googledrive)
-            find "$HOME/Library/CloudStorage" -maxdepth 1 -type d -name 'GoogleDrive-*' -print -quit 2>/dev/null \
-                || ssr::die "Google Drive folder not found under ~/Library/CloudStorage"
+            ssr::cloud::resolve_storage_pattern 'GoogleDrive-*' 'Google Drive' ''
             ;;
         onedrive)
-            find "$HOME/Library/CloudStorage" -maxdepth 1 -type d -name 'OneDrive-*' -print -quit 2>/dev/null \
-                || ssr::die "OneDrive folder not found under ~/Library/CloudStorage"
+            ssr::cloud::resolve_storage_pattern 'OneDrive-*' 'OneDrive' ''
             ;;
         custom)
             [[ -n "$custom" ]] || ssr::die "SSR_CLOUD_PROVIDER=custom requires SSR_CLOUD_PATH"
+            case "$custom" in
+                '~' | '~'/*) custom="${custom/#\~/$HOME}" ;;
+            esac
+            ssr::validate_path "$custom"
             printf '%s\n' "$custom"
             ;;
         *)