fix(tools): flatten nested anyOf schemas for Vertex AI compatibility

Claude API on Vertex AI (Cloud Code Assist) rejects nested anyOf schemas
as invalid JSON Schema draft 2020-12. This change:

- Add tryFlattenLiteralAnyOf() to convert Type.Union([Type.Literal(...)])
  patterns from anyOf with const values to flat enum arrays
- Update stringEnum helper in bash-tools to use Type.Unsafe with flat enum
- Flatten BrowserActSchema from discriminated union to single object
- Simplify TelegramToolSchema to use Type.String() for IDs

Fixes 400 errors when sending messages through WhatsApp/Telegram providers.

src/agents/tools/browser-tool.ts

@@ -28,74 +28,55 @@ import {
   readStringParam,
 } from "./common.js";
 
-const BrowserActSchema = Type.Union([
-  Type.Object({
-    kind: Type.Literal("click"),
-    ref: Type.String(),
-    targetId: Type.Optional(Type.String()),
-    doubleClick: Type.Optional(Type.Boolean()),
-    button: Type.Optional(Type.String()),
-    modifiers: Type.Optional(Type.Array(Type.String())),
+// NOTE: Using a flattened object schema instead of Type.Union([Type.Object(...), ...])
+// because Claude API on Vertex AI rejects nested anyOf schemas as invalid JSON Schema.
+// The discriminator (kind) determines which properties are relevant; runtime validates.
+const BrowserActSchema = Type.Object({
+  kind: Type.Unsafe<string>({
+    type: "string",
+    enum: [
+      "click",
+      "type",
+      "press",
+      "hover",
+      "drag",
+      "select",
+      "fill",
+      "resize",
+      "wait",
+      "evaluate",
+      "close",
+    ],
   }),
-  Type.Object({
-    kind: Type.Literal("type"),
-    ref: Type.String(),
-    text: Type.String(),
-    targetId: Type.Optional(Type.String()),
-    submit: Type.Optional(Type.Boolean()),
-    slowly: Type.Optional(Type.Boolean()),
-  }),
-  Type.Object({
-    kind: Type.Literal("press"),
-    key: Type.String(),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("hover"),
-    ref: Type.String(),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("drag"),
-    startRef: Type.String(),
-    endRef: Type.String(),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("select"),
-    ref: Type.String(),
-    values: Type.Array(Type.String()),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("fill"),
-    fields: Type.Array(Type.Record(Type.String(), Type.Unknown())),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("resize"),
-    width: Type.Number(),
-    height: Type.Number(),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("wait"),
-    timeMs: Type.Optional(Type.Number()),
-    text: Type.Optional(Type.String()),
-    textGone: Type.Optional(Type.String()),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("evaluate"),
-    fn: Type.String(),
-    ref: Type.Optional(Type.String()),
-    targetId: Type.Optional(Type.String()),
-  }),
-  Type.Object({
-    kind: Type.Literal("close"),
-    targetId: Type.Optional(Type.String()),
-  }),
-]);
+  // Common fields
+  targetId: Type.Optional(Type.String()),
+  ref: Type.Optional(Type.String()),
+  // click
+  doubleClick: Type.Optional(Type.Boolean()),
+  button: Type.Optional(Type.String()),
+  modifiers: Type.Optional(Type.Array(Type.String())),
+  // type
+  text: Type.Optional(Type.String()),
+  submit: Type.Optional(Type.Boolean()),
+  slowly: Type.Optional(Type.Boolean()),
+  // press
+  key: Type.Optional(Type.String()),
+  // drag
+  startRef: Type.Optional(Type.String()),
+  endRef: Type.Optional(Type.String()),
+  // select
+  values: Type.Optional(Type.Array(Type.String())),
+  // fill - use permissive array of objects
+  fields: Type.Optional(Type.Array(Type.Object({}, { additionalProperties: true }))),
+  // resize
+  width: Type.Optional(Type.Number()),
+  height: Type.Optional(Type.Number()),
+  // wait
+  timeMs: Type.Optional(Type.Number()),
+  textGone: Type.Optional(Type.String()),
+  // evaluate
+  fn: Type.Optional(Type.String()),
+});
 
 // IMPORTANT: OpenAI function tool schemas must have a top-level `type: "object"`.
 // A root-level `Type.Union([...])` compiles to `{ anyOf: [...] }` (no `type`),

src/agents/tools/telegram-schema.ts

@@ -2,11 +2,14 @@ import { Type } from "@sinclair/typebox";
 
 import { createReactionSchema } from "./reaction-schema.js";
 
+// NOTE: chatId and messageId use Type.String() instead of Type.Union([Type.String(), Type.Number()])
+// because nested anyOf schemas cause JSON Schema validation failures with Claude API on Vertex AI.
+// Telegram IDs are coerced to strings at runtime in telegram-actions.ts.
 export const TelegramToolSchema = Type.Union([
   createReactionSchema({
     ids: {
-      chatId: Type.Union([Type.String(), Type.Number()]),
-      messageId: Type.Union([Type.String(), Type.Number()]),
+      chatId: Type.String(),
+      messageId: Type.String(),
     },
     includeRemove: true,
   }),