feat(ai): compat entrypoint, core-only root barrel (phase 5)

The root barrel is now core-only and side-effect free: types,
createModels/createProvider, auth substrate, lazyStream/lazyApi, faux,
utils. Generated catalogs, api-registry, env-api-keys, images, global
stream functions, and per-API lazy wrappers leave the root.

New @earendil-works/pi-ai/compat preserves the old surface verbatim as
a strict superset of the root: api-dispatch stream/complete with env
key injection, the builtin registration side effect (skip-if-present so
it cannot clobber earlier overrides), deprecated getModel/getModels/
getProviders aliases of the new getBuiltin* reads in providers/all,
lazy api wrappers + setBedrockProviderModule, and image generation.
Compat dies with the coding-agent ModelManager migration.

Packaging: exports map gains ./compat, ./providers/*, ./api/*;
sideEffects array lists only the effectful modules.

Old-global imports across agent/coding-agent/examples and pi-ai tests
switch to /compat (path-only; compat is a superset). The coding-agent
extension loader resolves the pi-ai ROOT specifier to compat, so
existing user extensions using the old global API keep working at
runtime until compat is removed. vitest configs alias /compat to src;
browser smoke imports old globals from /compat.

packages/coding-agent/test/agent-session-auto-compaction-queue.test.ts

@@ -2,7 +2,7 @@ import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { Agent } from "@earendil-works/pi-agent-core";
-import { type AssistantMessage, getModel } from "@earendil-works/pi-ai";
+import { type AssistantMessage, getModel } from "@earendil-works/pi-ai/compat";
 import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";
 import { AuthStorage } from "../src/core/auth-storage.ts";

packages/coding-agent/test/agent-session-branching.test.ts

@@ -10,7 +10,7 @@
 import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import type { AgentSession } from "../src/core/agent-session.ts";
 import {

packages/coding-agent/test/agent-session-compaction.test.ts

@@ -11,7 +11,7 @@ import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { Agent } from "@earendil-works/pi-agent-core";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { AgentSession, type AgentSessionEvent } from "../src/core/agent-session.ts";
 import { AuthStorage } from "../src/core/auth-storage.ts";

packages/coding-agent/test/agent-session-concurrent.test.ts

@@ -13,7 +13,7 @@ import {
 	getModel,
 	type ImageContent,
 	type TextContent,
-} from "@earendil-works/pi-ai";
+} from "@earendil-works/pi-ai/compat";
 import { Type } from "typebox";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";

packages/coding-agent/test/agent-session-dynamic-provider.test.ts

@@ -1,7 +1,7 @@
 import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { AuthStorage } from "../src/core/auth-storage.ts";
 import { DefaultResourceLoader } from "../src/core/resource-loader.ts";

packages/coding-agent/test/agent-session-dynamic-tools.test.ts

@@ -1,7 +1,7 @@
 import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { Type } from "typebox";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { DefaultResourceLoader } from "../src/core/resource-loader.ts";

packages/coding-agent/test/agent-session-retry.test.ts

@@ -2,7 +2,7 @@ import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { Agent, type AgentEvent, type AgentTool } from "@earendil-works/pi-agent-core";
-import { type AssistantMessage, type AssistantMessageEvent, EventStream, getModel } from "@earendil-works/pi-ai";
+import { type AssistantMessage, type AssistantMessageEvent, EventStream, getModel } from "@earendil-works/pi-ai/compat";
 import { Type } from "typebox";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";

packages/coding-agent/test/agent-session-stats.test.ts

@@ -1,5 +1,5 @@
 import { Agent } from "@earendil-works/pi-agent-core";
-import { type AssistantMessage, getModel, type Usage } from "@earendil-works/pi-ai";
+import { type AssistantMessage, getModel, type Usage } from "@earendil-works/pi-ai/compat";
 import { describe, expect, it } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";
 import { AuthStorage } from "../src/core/auth-storage.ts";

packages/coding-agent/test/compaction-extensions.test.ts

@@ -6,7 +6,7 @@ import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
 import { Agent } from "@earendil-works/pi-agent-core";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";
 import { AuthStorage } from "../src/core/auth-storage.ts";

packages/coding-agent/test/compaction-summary-reasoning.test.ts

@@ -7,8 +7,8 @@ const { completeSimpleMock } = vi.hoisted(() => ({
 	completeSimpleMock: vi.fn(),
 }));
 
-vi.mock("@earendil-works/pi-ai", async (importOriginal) => {
-	const actual = await importOriginal<typeof import("@earendil-works/pi-ai")>();
+vi.mock("@earendil-works/pi-ai/compat", async (importOriginal) => {
+	const actual = await importOriginal<typeof import("@earendil-works/pi-ai/compat")>();
 	return {
 		...actual,
 		completeSimple: completeSimpleMock,

packages/coding-agent/test/compaction.test.ts

@@ -1,6 +1,6 @@
 import type { AgentMessage } from "@earendil-works/pi-agent-core";
-import type { AssistantMessage, Usage } from "@earendil-works/pi-ai";
-import { getModel } from "@earendil-works/pi-ai";
+import type { AssistantMessage, Usage } from "@earendil-works/pi-ai/compat";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { readFileSync } from "fs";
 import { join } from "path";
 import { beforeEach, describe, expect, it } from "vitest";

packages/coding-agent/test/model-registry.test.ts

@@ -1,8 +1,14 @@
 import { existsSync, mkdirSync, readFileSync, rmSync, writeFileSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import type { AnthropicMessagesCompat, Api, Context, Model, OpenAICompletionsCompat } from "@earendil-works/pi-ai";
-import { getApiProvider } from "@earendil-works/pi-ai";
+import type {
+	AnthropicMessagesCompat,
+	Api,
+	Context,
+	Model,
+	OpenAICompletionsCompat,
+} from "@earendil-works/pi-ai/compat";
+import { getApiProvider } from "@earendil-works/pi-ai/compat";
 import { getOAuthProvider } from "@earendil-works/pi-ai/oauth";
 import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
 import { AuthStorage } from "../src/core/auth-storage.ts";

packages/coding-agent/test/rpc-prompt-response-semantics.test.ts

@@ -8,7 +8,7 @@ import {
 	EventStream,
 	getModel,
 	type Model,
-} from "@earendil-works/pi-ai";
+} from "@earendil-works/pi-ai/compat";
 import { afterEach, describe, expect, it, vi } from "vitest";
 import { AgentSession } from "../src/core/agent-session.ts";
 import type { AgentSessionRuntime } from "../src/core/agent-session-runtime.ts";

packages/coding-agent/test/sdk-codex-cache-probe-tool-loop.ts

@@ -20,7 +20,7 @@ import {
 	type Model,
 	type SimpleStreamOptions,
 	Type,
-} from "@earendil-works/pi-ai";
+} from "@earendil-works/pi-ai/compat";
 import {
 	getOpenAICodexWebSocketDebugStats,
 	streamSimple as streamSimpleOpenAICodexResponses,

packages/coding-agent/test/sdk-session-manager.test.ts

@@ -1,7 +1,7 @@
 import { existsSync, mkdirSync, realpathSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { createAgentSession } from "../src/core/sdk.ts";
 import { SessionManager } from "../src/core/session-manager.ts";

packages/coding-agent/test/suite/regressions/2835-tools-allowlist-filters-extension-tools.test.ts

@@ -1,7 +1,7 @@
 import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { Type } from "typebox";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import { DefaultResourceLoader } from "../../../src/core/resource-loader.ts";

packages/coding-agent/test/suite/regressions/3592-no-builtin-tools-keeps-extension-tools.test.ts

@@ -1,7 +1,7 @@
 import { existsSync, mkdirSync, rmSync } from "node:fs";
 import { tmpdir } from "node:os";
 import { join } from "node:path";
-import { getModel } from "@earendil-works/pi-ai";
+import { getModel } from "@earendil-works/pi-ai/compat";
 import { Type } from "typebox";
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 import {

packages/coding-agent/test/utilities.ts

@@ -6,7 +6,7 @@ import { chmodSync, existsSync, mkdirSync, readFileSync, rmSync, writeFileSync }
 import { homedir, tmpdir } from "node:os";
 import { dirname, join } from "node:path";
 import { Agent } from "@earendil-works/pi-agent-core";
-import { getModel, type OAuthCredentials, type OAuthProvider } from "@earendil-works/pi-ai";
+import { getModel, type OAuthCredentials, type OAuthProvider } from "@earendil-works/pi-ai/compat";
 import { getOAuthApiKey } from "@earendil-works/pi-ai/oauth";
 import { AgentSession } from "../src/core/agent-session.ts";
 import { AuthStorage } from "../src/core/auth-storage.ts";