refactor: remove legacy symlink migration code

Remove migrateStorageIfNeeded() which created symlinks from
~/.uncaged/workflow → ~/.uwf and ~/.uncaged/json-cas → ~/.ocas.

This was temporary migration support. Users who still have old paths
can run a one-time copy manually.

Zero 'uncaged' references remain in active codebase.

packages/cli/src/cli.ts

@@ -30,9 +30,7 @@ import {
 import { parseTimeInput } from "./commands/thread-time-parser.js";
 import { cmdWorkflowAdd, cmdWorkflowList, cmdWorkflowShow } from "./commands/workflow.js";
 import { formatOutput, type OutputFormat } from "./format.js";
-import { migrateStorageIfNeeded, resolveStorageRoot } from "./store.js";
-
-migrateStorageIfNeeded();
+import { resolveStorageRoot } from "./store.js";
 
 function writeOutput(data: unknown): void {
   const fmt = program.opts().format as OutputFormat;