chore: migrate @uncaged/json-cas to @ocas/core, @uncaged/json-cas-fs to @ocas/fs

- Replace all package.json dependencies
- Update all imports across 7 packages + scripts
- cas_ref → ocas_ref in schema definitions
- listByType() adapted for ListEntry[] return type
- Update CLAUDE.md references

Fixes #585

packages/workflow-agent-claude-code/__tests__/session-detail.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, test } from "bun:test";
-import { createMemoryStore, walk } from "@uncaged/json-cas";
+import { createMemoryStore, walk } from "@ocas/core";
 import {
   parseClaudeCodeJsonOutput,
   parseClaudeCodeStreamOutput,