config: also extract ?w= from Host URL

config/config.go

@@ -653,6 +653,14 @@ func (c *Config) fixHostIfNeeded() error {
 }
 
 func workspaceIDFromQuery(q url.Values) string {
+	// ?w= is the unified workspace addressing query parameter. It supersedes
+	// the older ?o=/?workspace_id= forms and accepts a broader range of
+	// workspace identifier formats — both classic numeric workspace IDs and
+	// other identifier formats the server understands — so we don't apply the
+	// numeric-only validation that we use for ?o=/?workspace_id=.
+	if v := q.Get("w"); v != "" {
+		return v
+	}
 	for _, key := range []string{"o", "workspace_id"} {
 		v := q.Get(key)
 		if v == "" {

config/config_test.go

@@ -1362,6 +1362,31 @@ func TestConfig_fixHostIfNeeded_extractsWorkspaceIDFromQuery(t *testing.T) {
 			host:     "https://acme.databricks.net/?o=notanumber",
 			wantHost: "https://acme.databricks.net",
 		},
+		{
+			name:            "?w= with numeric value promoted to WorkspaceID",
+			host:            "https://acme.databricks.net/?w=12345",
+			wantHost:        "https://acme.databricks.net",
+			wantWorkspaceID: "12345",
+		},
+		{
+			name:            "?w= with non-numeric value promoted to WorkspaceID",
+			host:            "https://acme.databricks.net/?w=7a99b43c-b46c-432b-b0a7-814217701909",
+			wantHost:        "https://acme.databricks.net",
+			wantWorkspaceID: "7a99b43c-b46c-432b-b0a7-814217701909",
+		},
+		{
+			name:            "?w= takes precedence over ?o=",
+			host:            "https://acme.databricks.net/?w=12345&o=99999",
+			wantHost:        "https://acme.databricks.net",
+			wantWorkspaceID: "12345",
+		},
+		{
+			name:            "existing WorkspaceID is preserved over ?w=",
+			host:            "https://acme.databricks.net/?w=12345",
+			workspaceID:     "99999",
+			wantHost:        "https://acme.databricks.net",
+			wantWorkspaceID: "99999",
+		},
 		{
 			name:     "host without query is unchanged",
 			host:     "https://acme.databricks.net",