chore(work): finish 06-sandcastle-reviewer-prompt

docs/work/2026-05-14-library-evaluation-policy/06-sandcastle-reviewer-prompt/_story.md

@@ -3,7 +3,7 @@ id: 06-sandcastle-reviewer-prompt
 epic: 2026-05-14-library-evaluation-policy
 title: Sandcastle reviewer prompt — Library-trace check section
 type: technical-story
-status: todo
+status: done
 feature: tooling
 depends-on: [02-pre-commit-check-script]
 blocks: []
@@ -38,4 +38,4 @@ The sandcastle reviewer runs in a clean sandbox where `git diff --cached` may no
 
 ## Tasks
 
-- [ ] Add `--staged-against <base>` flag to `check.mjs` (switches from `git diff --cached` to `git diff <base>...HEAD`); add a test covering `--staged-against` mode (temp git repo fixture, new feature-tier dep, no trace → exit 1); append "Library-trace check" section to `.sandcastle/reviewer.prompt.md` with the `node scripts/library-decisions/check.mjs --staged-against <base>` invocation and reject instruction; all gates pass on this single commit.
+- [x] Add `--staged-against <base>` flag to `check.mjs` (switches from `git diff --cached` to `git diff <base>...HEAD`); add a test covering `--staged-against` mode (temp git repo fixture, new feature-tier dep, no trace → exit 1); append "Library-trace check" section to `.sandcastle/reviewer.prompt.md` with the `node scripts/library-decisions/check.mjs --staged-against <base>` invocation and reject instruction; all gates pass on this single commit.

docs/work/_state.json

@@ -1,5 +1,5 @@
 {
-  "updated_at": "2026-05-14T05:53:07.803Z",
+  "updated_at": "2026-05-14T05:58:56.574Z",
   "epics": {
     "2026-05-13-binder-wrap-helper": {
       "status": "done",
@@ -97,10 +97,10 @@
           ]
         },
         "06-sandcastle-reviewer-prompt": {
-          "status": "todo",
+          "status": "done",
           "title": "Sandcastle reviewer prompt — Library-trace check section",
           "ac_total": 1,
-          "ac_completed": 0,
+          "ac_completed": 1,
           "depends_on": [
             "02-pre-commit-check-script"
           ],
@@ -155,11 +155,6 @@
     }
   },
   "ready": [
-    {
-      "epic": "2026-05-14-library-evaluation-policy",
-      "story": "06-sandcastle-reviewer-prompt",
-      "title": "Sandcastle reviewer prompt — Library-trace check section"
-    },
     {
       "epic": "2026-05-14-library-evaluation-policy",
       "story": "07-generator-pre-shipped-traces",