fix: backup storage relative to vault parent + global capture click handler for close button

- _backup_file: resolve relative backup path against vault parent (survives CWD changes)
- _get_backup_root: same resolution logic for listing
- backups.js: global document-level capture-phase click handler for .backup-close-btn
  (works regardless of innerHTML replacements, text node targets, or event bubbling)

backend/main.py

@@ -715,22 +715,29 @@ def _resolve_safe_path(vault_root: Path, relative_path: str) -> Path:
 def _backup_file(file_path: Path, vault_name: str, relative_path: str):
     """Create a timestamped backup of a file before modification.
 
-    Backups are stored in .obsigate-backup/{vault}/{relative_path}.{timestamp}.bak
+    Backups are stored in {backup_root}/{vault}/{relative_path}.{timestamp}.bak
     Silently skips if the file doesn't exist or can't be read.
     """
     try:
         if not file_path.exists() or not file_path.is_file():
+            logger.debug(f"Backup skipped: file not found {file_path}")
             return
         backup_root = Path(os.environ.get("OBSIGATE_BACKUP_DIR", ".obsigate-backup"))
+        # Resolve relative to vault root for consistency
+        if not backup_root.is_absolute():
+            vault_data = get_vault_data(vault_name)
+            if vault_data:
+                vault_root_path = Path(vault_data["path"])
+                backup_root = vault_root_path.parent / backup_root
         backup_dir = backup_root / vault_name / Path(relative_path).parent
         backup_dir.mkdir(parents=True, exist_ok=True)
         timestamp = int(time.time())
         backup_name = f"{file_path.name}.{timestamp}.bak"
         backup_path = backup_dir / backup_name
         shutil.copy2(file_path, backup_path)
-        logger.debug(f"Backed up {relative_path} to {backup_path}")
+        logger.info(f"Backup created: {relative_path} -> {backup_path}")
     except Exception as e:
-        logger.warning(f"Failed to backup {relative_path}: {e}")
+        logger.warning(f"Failed to backup {relative_path} (vault={vault_name}): {e}", exc_info=True)
 
 
 def _check_vault_writable(vault_root: Path) -> bool:
@@ -1928,8 +1935,26 @@ async def api_file_move(
 # ---------------------------------------------------------------------------
 
 def _get_backup_root() -> Path:
-    """Return the backup root directory as configured."""
-    return Path(os.environ.get("OBSIGATE_BACKUP_DIR", ".obsigate-backup"))
+    """Return the backup root directory as configured.
+    
+    If the configured path is relative, it is resolved relative to the
+    first vault's parent directory for consistency with _backup_file.
+    """
+    root = Path(os.environ.get("OBSIGATE_BACKUP_DIR", ".obsigate-backup"))
+    if not root.is_absolute():
+        # Resolve relative to the first vault's parent so backups survive CWD changes
+        try:
+            from backend.indexer import get_vault_data as _get_vd
+            vaults = index  # use the module-level index
+            if vaults:
+                first_name = next(iter(vaults.keys()))
+                vd = _get_vd(first_name)
+                if vd:
+                    vault_parent = Path(vd["path"]).parent
+                    root = vault_parent / root
+        except Exception:
+            pass  # fall back to relative
+    return root
 
 
 def _get_backup_dir(vault_name: str, relative_path: str) -> Path: