feat: introduced omptype validation package and migrated workspace dependencies

- Introduce `@oh-my-pi/omptype` as a new ArkType-compatible schema validation package featuring a lazy JIT runtime, JSON Schema emission, and compatibility adapters.
- Replace `arktype` across workspace packages and test utilities with `@oh-my-pi/omptype`.
- Add benchmark suites, tests, and documentation for the new validation engine and adapters.
- Update workspace build, test runner, and release configurations to include the new package.

packages/coding-agent/src/edit/hashline/params.ts

@@ -3,7 +3,7 @@
  * deliberately permissive (allows extra keys) so providers can attach extra
  * keys without rejection; only `input` is required.
  */
-import { type } from "arktype";
+import { type } from "@oh-my-pi/omptype";
 
 export const hashlineEditParamsSchema = type({
 	input: "string",

packages/coding-agent/src/edit/modes/apply-patch.ts

@@ -8,7 +8,7 @@
  * the `patch` mode.
  */
 
-import { type } from "arktype";
+import { type } from "@oh-my-pi/omptype";
 import { parseApplyPatch, parseApplyPatchStreaming } from "../apply-patch/parser";
 import { ApplyPatchError } from "../diff";
 import type { PatchEditEntry } from "./patch";

packages/coding-agent/src/edit/modes/patch.ts

@@ -7,9 +7,9 @@
 
 import * as fs from "node:fs";
 import * as path from "node:path";
+import { type } from "@oh-my-pi/omptype";
 import type { AgentToolResult } from "@oh-my-pi/pi-agent-core";
 import { isEnoent } from "@oh-my-pi/pi-utils";
-import { type } from "arktype";
 import {
 	type FileDiagnosticsResult,
 	flushLspWritethroughBatch,

packages/coding-agent/src/edit/modes/replace.ts

@@ -4,8 +4,9 @@
  * Provides both character-level and line-level fuzzy matching with progressive
  * fallback strategies for finding text in files.
  */
+
+import { type } from "@oh-my-pi/omptype";
 import type { AgentToolResult } from "@oh-my-pi/pi-agent-core";
-import { type } from "arktype";
 import type { FileDiagnosticsResult, WritethroughCallback, WritethroughDeferredHandle } from "../../lsp";
 import type { ToolSession } from "../../tools";
 import { routeWriteThroughBridge } from "../../tools/acp-bridge";