fix(vitest-certa-bridge): address arch review findings

Fixes all 21 findings from the architectural review of PR #9094.

API surface (A/B):
- Remove "import" ESM condition from ./electron subpath (points to CJS
  build to avoid __dirname/require() breakage; kept for Vite resolution)
- Gate ./callbackRegistry subpath to public-only barrel (new
  callbackRegistryPublic.ts re-exports only registerBackendCallback +
  getCallbacksRegisteredOnBackend)
- Mark executeRegisteredCallback/clearCallbacks/dispatchCallback @internal
- Mark BridgeRequest/BridgeResponse @internal; remove from root barrel
- Add @beta TSDoc tags to all public API symbols
- Fix CertaBackendCallback type: unknown (subsumes Promise<unknown>)
- Add GrepMode = "include" | "exclude" type; replace invertGrep: boolean
- Mark RendererTestResults/RendererHarnessOptions @internal; remove from
  electron/index.ts public barrel

Concurrency (C):
- C1: Replace shared mutable results[] in runner.ts with Promise.all/flat
- C2: Initialize backendReady = Promise.resolve() (not undefined)
- C3/D7/E7: Normalize backendInitModule resolution in session.ts
- C4: Use Symbol.for("@itwin/vitest-certa-bridge/callbacks") registry key
- C5: Guard render-process-gone handler with testResultsReceived flag
- C6: Surface backend init errors via console.error instead of swallowing

Error signaling (D):
- D1/E2: afterAll catch increments failed count + pushes to errors
- D2: Wrap setup file require in try/catch with early IPC send on failure
- D3: Add res.ok guard before res.json() in injected bridge script
- D4: Write crash result JSON on render-process-gone before process.exit
- D5: Fix isSilentTimeout false-positive: require skipped === 0
- D6: Count unhandled rejections; surface in shard summary

Design patterns (E):
- E1: Replace invertGrep: boolean with grepMode: GrepMode everywhere
- E3: Extract dispatchCallback() shared helper (deduplicates token
  validation across HTTP middleware and Electron IPC handler)
- E4: Extract shared loadEnv utility with dotenv-expand v5/v9 compat
- E5: Memoize bridge transport detection in client.ts
- E6: Move legacyGetTokenCallbackName comment; keep local to certaBackend

Scope (F):
- F6: Remove stale @itwin/certa devDependency from core/electron

Additional fixes found during CI:
- Restore "getToken" legacy callback registration in full-stack-tests/core
  and ecschema-rpc-interface backends for @itwin/oidc-signin-tool compat
- Keep "import" condition on ./electron subpath (Vite needs it to resolve
  the package; point it at CJS to preserve __dirname/require() at runtime)
- rush update after adding new source files to vitest-certa-bridge

Author: hl662

common/api/core-backend.api.md

@@ -75,7 +75,6 @@ import { DrawingProps } from '@itwin/core-common';
 import { EcefLocation } from '@itwin/core-common';
 import { EcefLocationProps } from '@itwin/core-common';
 import { ECSchemaProps } from '@itwin/core-common';
-import { ECSpecVersion } from '@itwin/ecschema-metadata';
 import { ECSqlReader } from '@itwin/core-common';
 import { ECSqlReaderBase } from '@itwin/core-common';
 import { ECSqlValueType } from '@itwin/core-common';
@@ -431,7 +430,6 @@ export interface AvailableCoordinateReferenceSystemProps {
     deprecated: boolean;
     description: string;
     name: string;
-    unit?: string;
 }
 
 // @beta (undocumented)
@@ -734,25 +732,6 @@ export class BriefcaseManager {
     static storeSchemasForSemanticRebase<T extends LocalFileName[] | string[]>(db: BriefcaseDb, txnId: string, schemaFileNames: T): void;
 }
 
-// @beta
-export interface BulkDeleteElementsArgs {
-    skipFKConstraintValidations?: boolean;
-}
-
-// @beta
-export interface BulkDeleteElementsResult {
-    failedIds: Id64Set;
-    sqlDeleteStatus: DbResult;
-    status: BulkDeleteElementsStatus;
-}
-
-// @beta
-export enum BulkDeleteElementsStatus {
-    DeletionFailed = 2,
-    PartialSuccess = 1,
-    Success = 0
-}
-
 // @public
 export abstract class Callout extends DetailingSymbol {
     constructor(props: CalloutProps, iModel: IModelDb);
@@ -878,14 +857,6 @@ export class CategorySelector extends DefinitionElement {
 }
 
 // @beta
-export interface ChangeCache extends Disposable {
-    all(): IterableIterator<ChangeInstance>;
-    count(): number;
-    get(key: string): ChangeInstance | undefined;
-    set(key: string, value: ChangeInstance): void;
-}
-
-// @beta @deprecated
 export interface ChangedECInstance {
     // (undocumented)
     $meta?: ChangeMetaData;
@@ -927,12 +898,6 @@ export interface ChangeFormatArgs {
     includeTableName?: true;
 }
 
-// @beta
-export interface ChangeInstance {
-    $meta: ChangeMeta;
-    [key: string]: any;
-}
-
 // @beta
 export interface ChangeInstanceKey {
     changeType: "inserted" | "updated" | "deleted";
@@ -941,19 +906,6 @@ export interface ChangeInstanceKey {
 }
 
 // @beta
-export interface ChangeMeta {
-    changeFetchedPropNames: string[];
-    changeIndexes: number[];
-    instanceKey: string;
-    isIndirectChange: boolean;
-    op: SqliteChangeOp;
-    propFilter: PropertyFilter;
-    rowOptions?: RowFormatOptions;
-    stage: SqliteValueStage;
-    tables: string[];
-}
-
-// @beta @deprecated
 export interface ChangeMetaData {
     changeIndexes: number[];
     classFullName?: string;
@@ -969,7 +921,7 @@ export interface ChangesetArg extends IModelIdArg {
     readonly changeset: ChangesetIndexOrId;
 }
 
-// @beta @deprecated
+// @beta
 export class ChangesetECAdaptor implements Disposable {
     [Symbol.dispose](): void;
     constructor(reader: SqliteChangesetReader, disableMetaData?: boolean);
@@ -1007,58 +959,6 @@ export interface ChangesetRangeArg extends IModelIdArg {
     readonly range?: ChangesetRange;
 }
 
-// @beta
-export class ChangesetReader implements Disposable, ChangeSource {
-    [Symbol.dispose](): void;
-    clearClassNameFilters(): void;
-    clearOpCodeFilters(): void;
-    clearTableNameFilters(): void;
-    close(): void;
-    readonly db: AnyDb;
-    deleted?: ChangeInstance;
-    inserted?: ChangeInstance;
-    get isECTable(): boolean;
-    get isIndirectChange(): boolean;
-    get op(): SqliteChangeOp;
-    static openFile(args: {
-        readonly fileName: string;
-    } & ChangesetReaderArgs): ChangesetReader;
-    static openGroup(args: {
-        readonly changesetFiles: string[];
-    } & ChangesetReaderArgs): ChangesetReader;
-    static openInMemoryChanges(args: Omit<ChangesetReaderArgs, "db"> & {
-        db: IModelDb;
-    }): ChangesetReader;
-    static openLocalChanges(args: Omit<ChangesetReaderArgs, "db"> & {
-        db: IModelDb;
-        includeInMemoryChanges?: boolean;
-    }): ChangesetReader;
-    static openTxn(args: Omit<ChangesetReaderArgs, "db"> & {
-        db: IModelDb;
-        txnId: Id64String;
-    }): ChangesetReader;
-    setClassNameFilters(classNames: Set<string>): void;
-    setOpCodeFilters(ops: Set<SqliteChangeOp>): void;
-    setTableNameFilters(tableNames: Set<string>): void;
-    step(): boolean;
-    get tableName(): string;
-}
-
-// @beta
-export interface ChangesetReaderArgs {
-    readonly db: AnyDb;
-    readonly invert?: boolean;
-    readonly propFilter?: PropertyFilter;
-    readonly rowOptions?: RowFormatOptions;
-}
-
-// @beta
-export interface ChangeSource {
-    readonly deleted?: ChangeInstance;
-    readonly inserted?: ChangeInstance;
-    readonly op: SqliteChangeOp;
-}
-
 // @beta
 export interface ChangeSummary {
     // (undocumented)
@@ -1093,12 +993,6 @@ export class ChangeSummaryManager {
     static queryInstanceChange(iModel: BriefcaseDb, instanceChangeId: Id64String): InstanceChange;
 }
 
-// @beta (undocumented)
-export namespace ChangeUnifierCache {
-    export function createInMemoryCache(): ChangeCache;
-    export function createSqliteBackedCache(bufferedReadInstanceSizeInBytes?: number): ChangeCache;
-}
-
 // @beta
 export interface ChannelControl {
     // @internal (undocumented)
@@ -2353,15 +2247,15 @@ export abstract class DriverBundleElement extends InformationContentElement {
     static get className(): string;
 }
 
-// @beta @deprecated
+// @beta
 export interface ECChangeUnifierCache extends Disposable {
     all(): IterableIterator<ChangedECInstance>;
     count(): number;
     get(key: string): ChangedECInstance | undefined;
     set(key: string, value: ChangedECInstance): void;
 }
 
-// @beta @deprecated (undocumented)
+// @beta (undocumented)
 export namespace ECChangeUnifierCache {
     export function createInMemoryCache(): ECChangeUnifierCache;
     export function createSqliteBackedCache(db: AnyDb, bufferedReadInstanceSizeInBytes?: number): ECChangeUnifierCache;
@@ -2716,7 +2610,6 @@ export class EditTxn {
     deleteAspect(aspectInstanceIds: Id64Arg): void;
     deleteDefinitionElements(definitionElementIds: Id64Array): Id64Set;
     deleteElement(ids: Id64Arg): void;
-    deleteElements(ids: Id64Array, deleteOptions?: BulkDeleteElementsArgs): BulkDeleteElementsResult;
     deleteFileProperty(prop: FilePropertyProps): void;
     deleteModel(ids: Id64Arg): void;
     deleteRelationship(props: RelationshipProps): void;
@@ -2792,10 +2685,6 @@ class Element_2 extends Entity {
     // @beta
     protected static onBeforeOutputsHandledArg(arg: OnElementDependencyArg): void;
     // @beta
-    protected static onBulkChildDeleted(arg: OnBulkChildDeletedBatchArg): void;
-    // @beta
-    protected static onBulkDeleted(arg: OnBulkDeletedBatchArg): void;
-    // @beta
     protected static onChildAdd(_arg: OnChildElementPropsArg): void;
     // @beta
     protected static onChildAdded(arg: OnChildElementIdArg): void;
@@ -3814,12 +3703,8 @@ export function getAvailableCoordinateReferenceSystems(args: GetAvailableCoordin
 export interface GetAvailableCoordinateReferenceSystemsArgs {
     extent?: Range2dProps;
     includeWorld?: boolean;
-    unit?: string;
 }
 
-// @beta
-export function getAvailableCRSUnits(): string[];
-
 // @beta
 export interface GetWorkspaceContainerArgs extends WorkspaceContainerProps {
     accessToken: AccessToken;
@@ -4029,8 +3914,6 @@ export abstract class IModelDb extends IModel {
     exportSchema(args: ExportSchemaArgs): void;
     // @beta
     exportSchemas(outputDirectory: LocalFileName): void;
-    // @beta
-    exportSchemaXmlString(schemaName: string, ecSpecVersion?: ECSpecVersion): string | undefined;
     static findByFilename(fileName: LocalFileName): IModelDb | undefined;
     static findByKey(key: string): IModelDb;
     // @deprecated (undocumented)
@@ -5292,8 +5175,6 @@ export class Model extends Entity {
     // (undocumented)
     readonly name: string;
     // @beta
-    protected static onBulkModelEvents(arg: OnBulkModelEventsArg): void;
-    // @beta
     protected static onDelete(arg: OnModelIdArg): void;
     // @beta
     protected static onDeleted(arg: OnModelIdArg): void;
@@ -5437,43 +5318,6 @@ export interface OnAspectPropsArg extends OnAspectArg {
     props: Readonly<ElementAspectProps>;
 }
 
-// @beta
-export interface OnBulkChildDeleteArg {
-    childId: Id64String;
-    parentId: Id64String;
-}
-
-// @beta
-export interface OnBulkChildDeletedBatchArg {
-    elements: OnBulkChildDeleteArg[];
-    iModel: IModelDb;
-}
-
-// @beta
-export interface OnBulkDeleteArg {
-    federationGuid?: GuidString;
-    id: Id64String;
-    model: Id64String;
-    subModelId?: Id64String;
-}
-
-// @beta
-export interface OnBulkDeletedBatchArg {
-    elements: OnBulkDeleteArg[];
-    iModel: IModelDb;
-}
-
-// @beta
-export interface OnBulkDeletedElementsArg extends OnModelIdArg {
-    elementIds: Id64String[];
-}
-
-// @beta
-export interface OnBulkModelEventsArg extends OnModelArg {
-    deletedElementsByModel?: OnBulkDeletedElementsArg[];
-    deletedModelIds?: Id64String[];
-}
-
 // @beta
 export interface OnChildElementArg extends OnElementArg {
     // (undocumented)
@@ -5575,15 +5419,6 @@ export class OrthographicViewDefinition extends SpatialViewDefinition {
 export function parseTextAnnotationData(json: string | undefined): VersionedJSON<TextAnnotationProps> | undefined;
 
 // @beta
-export class PartialChangeUnifier implements Disposable {
-    [Symbol.dispose](): void;
-    constructor(_cache?: ChangeCache);
-    appendFrom(source: ChangeSource): void;
-    get instanceCount(): number;
-    get instances(): IterableIterator<ChangeInstance>;
-}
-
-// @beta @deprecated
 export class PartialECChangeUnifier implements Disposable {
     [Symbol.dispose](): void;
     constructor(_db: AnyDb, _cache?: ECChangeUnifierCache);
@@ -5770,13 +5605,6 @@ export interface ProjectInformationRecordCreateArgs extends ProjectInformation {
     parentSubjectId: Id64String;
 }
 
-// @beta
-export enum PropertyFilter {
-    All = 0,
-    BisCoreElement = 1,
-    InstanceKey = 2
-}
-
 // @public @preview
 export type PropertyHandler = (name: string, property: Property) => void;
 
@@ -5884,7 +5712,6 @@ export type QueryWorkspaceResourcesCallback = (resources: Iterable<{
 
 // @alpha
 export interface RebaseHandler {
-    dispose?(): void;
     recompute(txn: TxnProps): Promise<void>;
     shouldReinstate(txn: TxnProps): boolean;
 }
@@ -5898,7 +5725,6 @@ export class RebaseManager {
         handler: (args: RebaseChangesetConflictArgs) => DbConflictResolution | undefined;
     }): void;
     canAbort(): boolean;
-    dispose(): void;
     inProgress(): boolean;
     get isAborting(): boolean;
     get isMerging(): boolean;
@@ -6138,13 +5964,6 @@ export class RoleModel extends Model {
     static get className(): string;
 }
 
-// @beta
-export interface RowFormatOptions {
-    abbreviateBlobs?: boolean;
-    classIdsToClassNames?: boolean;
-    useJsName?: boolean;
-}
-
 // @public
 export class RpcTrace {
     static get currentActivity(): RpcActivity | undefined;
@@ -6839,9 +6658,7 @@ export class SpatialViewDefinition extends ViewDefinition3d {
     // @deprecated (undocumented)
     static insertWithCamera(iModelDb: IModelDb, definitionModelId: Id64String, name: string, modelSelectorId: Id64String, categorySelectorId: Id64String, displayStyleId: Id64String, range: Range3d, standardView?: StandardViewIndex, cameraAngle?: number): Id64String;
     loadModelSelector(): ModelSelector;
-    modelSelector: RelatedElementProps;
-    get modelSelectorId(): Id64String;
-    set modelSelectorId(id: Id64String);
+    modelSelectorId: Id64String;
     // @beta (undocumented)
     static readonly requiredReferenceKeys: ReadonlyArray<string>;
     // @alpha (undocumented)
@@ -7796,9 +7613,7 @@ export class ViewAttachmentLabel extends DetailingSymbol {
 // @public @preview
 export abstract class ViewDefinition extends DefinitionElement {
     protected constructor(props: ViewDefinitionProps, iModel: IModelDb);
-    categorySelector: RelatedElementProps;
-    get categorySelectorId(): Id64String;
-    set categorySelectorId(id: Id64String);
+    categorySelectorId: Id64String;
     // (undocumented)
     static get className(): string;
     // (undocumented)
@@ -7809,9 +7624,7 @@ export abstract class ViewDefinition extends DefinitionElement {
     // @beta
     static deserialize(props: DeserializeEntityArgs): ViewDefinitionProps;
     abstract get details(): ViewDetails;
-    displayStyle: RelatedElementProps;
-    get displayStyleId(): Id64String;
-    set displayStyleId(id: Id64String);
+    displayStyleId: Id64String;
     getAuxiliaryCoordinateSystemId(): Id64String;
     isDrawingView(): this is DrawingViewDefinition;
     isSpatialView(): this is SpatialViewDefinition;
@@ -7836,9 +7649,7 @@ export abstract class ViewDefinition extends DefinitionElement {
 export class ViewDefinition2d extends ViewDefinition {
     protected constructor(props: ViewDefinition2dProps, iModel: IModelDb);
     angle: Angle;
-    baseModel: RelatedElementProps;
-    get baseModelId(): Id64String;
-    set baseModelId(id: Id64String);
+    baseModelId: Id64String;
     // (undocumented)
     static get className(): string;
     // (undocumented)

common/api/core-bentley.api.md

@@ -1831,9 +1831,6 @@ export function using<T extends IDisposable, TResult>(resources: T | T[], func:
 // @public
 export function utf8ToString(utf8: Uint8Array): string | undefined;
 
-// @beta
-export function wrapTimerCallback(timerPromises: Set<Promise<void>>, callback: () => Promise<void>): Promise<void>;
-
 // @public
 export class YieldManager {
     constructor(options?: YieldManagerOptions);