refactor: remove all uncaged codename references

- Remove UNCAGED_CAS_DIR and UNCAGED_WORKFLOW_STORAGE_ROOT env var fallbacks
- Tests updated to use OCAS_DIR / UWF_STORAGE_ROOT
- All docs, READMEs, scripts, workflows, skills updated
- Only symlink migration code retains .uncaged paths (functional requirement)

Closes #12 (Phase 5 complete)

packages/cli/src/__tests__/adapter-json-roundtrip.test.ts

@@ -67,7 +67,7 @@ describe("C1: adapter JSON round-trip integration", () => {
       prompt: "Test round-trip task",
     });
 
-    process.env.UNCAGED_CAS_DIR = casDir;
+    process.env.OCAS_DIR = casDir;
 
     const threadId = "01ROUNDTRIPTEST0000000000" as ThreadId;
     await seedThreads(tmpDir, { [threadId]: startHash });
@@ -134,7 +134,7 @@ describe("C1: adapter JSON round-trip integration", () => {
           env: {
             ...process.env,
             WORKFLOW_STORAGE_ROOT: tmpDir,
-            UNCAGED_CAS_DIR: casDir,
+            OCAS_DIR: casDir,
           },
           cwd: tmpDir,
           timeout: 30000,