feat(cli): unify uwf CAS store with global json-cas store

This resolves issue #573 by moving uwf's CAS directory from
~/.uncaged/workflow/cas/ to the shared ~/.uncaged/json-cas/ location.

Changes:
- Added getGlobalCasDir() function with UNCAGED_CAS_DIR support
- Updated createUwfStore() to use global CAS directory
- Added comprehensive test coverage (11 new tests)
- Updated all existing tests for environment isolation
- Updated documentation (CLAUDE.md, README.md)

Benefits:
- Cross-tool visibility: json-cas CLI can read uwf-created nodes
- Schema sharing: both tools access same schema registry
- Future-proofing: enables json-cas render/verbose for uwf data

Fixes #573

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

packages/cli-workflow/src/__tests__/thread-read-xml-tags.test.ts

@@ -53,6 +53,8 @@ const DETAIL_SCHEMA = {
 async function makeUwfStore(storageRoot: string): Promise<UwfStore> {
   const casDir = join(storageRoot, "cas");
   await mkdir(casDir, { recursive: true });
+  // Set UNCAGED_CAS_DIR to use the test's CAS directory
+  process.env.UNCAGED_CAS_DIR = casDir;
   const store = createFsStore(casDir);
   const schemas = await registerUwfSchemas(store);
   return { storageRoot, store, schemas };
@@ -696,7 +698,7 @@ describe("thread read XML tag isolation", () => {
         agent: "uwf-test",
         startedAtMs: 1000000000000,
         completedAtMs: 1000000005000,
-      assembledPrompt: null,
+        assembledPrompt: null,
       })) as CasRef;
       steps.push(step);
       prev = step;

packages/cli-workflow/src/cli.ts

@@ -373,7 +373,12 @@ step
         process.stderr.write("invalid --quota: must be a positive integer\n");
         process.exit(1);
       }
-      const markdown = await cmdStepRead(storageRoot, stepHash as CasRef, quota, opts.prompt === true);
+      const markdown = await cmdStepRead(
+        storageRoot,
+        stepHash as CasRef,
+        quota,
+        opts.prompt === true,
+      );
       process.stdout.write(markdown.endsWith("\n") ? markdown : `${markdown}\n`);
     });
   });

packages/cli-workflow/src/commands/skill.ts

@@ -1,7 +1,7 @@
 export {
-  generateBootstrapReference as cmdSkillBootstrap,
   generateAdapterReference as cmdSkillAdapter,
   generateAuthorReference as cmdSkillAuthor,
+  generateBootstrapReference as cmdSkillBootstrap,
   generateDeveloperReference as cmdSkillDeveloper,
   generateUserReference as cmdSkillUser,
 } from "@uncaged/workflow-util";

packages/cli-workflow/src/commands/step.ts

@@ -311,7 +311,10 @@ export async function cmdStepRead(
     if (promptNode === null) {
       return `# Step ${stepHash}\n\n_Prompt CAS node not found: ${promptRef}_`;
     }
-    const promptText = typeof promptNode.payload === "string" ? promptNode.payload : JSON.stringify(promptNode.payload);
+    const promptText =
+      typeof promptNode.payload === "string"
+        ? promptNode.payload
+        : JSON.stringify(promptNode.payload);
     return `# Step ${stepHash}\n\n**Role:** ${payload.role}\n**Agent:** ${payload.agent}\n\n## Prompt\n\n${promptText}`;
   }