Move adapter implementations into shared workspace packages

Extract claude-local and codex-local adapter code from cli/server/ui
into packages/adapters/ and packages/adapter-utils/. CLI, server, and
UI now import shared adapter logic instead of duplicating it. Removes
~1100 lines of duplicated code across packages. Register new packages
in pnpm workspace.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/adapter-utils/src/index.ts

@@ -0,0 +1,13 @@
+export type {
+  AdapterAgent,
+  AdapterRuntime,
+  UsageSummary,
+  AdapterExecutionResult,
+  AdapterInvocationMeta,
+  AdapterExecutionContext,
+  ServerAdapterModule,
+  TranscriptEntry,
+  StdoutLineParser,
+  CLIAdapterModule,
+  CreateConfigValues,
+} from "./types.js";