fix: address second-pass review nits (3 storage tests + doc cleanup)

Second-pass review found 1 NOT-READY and 2 READY-TO-MERGE. The NOT-
READY concerns were two spec over-claims that I'm closing now by
ADDING coverage (rather than narrowing the spec):

FR-026 storage list (document.cookie, indexedDB, Cache API):
Added 3 new security tests in src/lib/anthropic-direct.test.ts:
- does NOT touch document.cookie (spies on getter+setter)
- does NOT touch indexedDB (stubs open/deleteDatabase to throw)
- does NOT touch the Cache API (stubs caches.open/match to throw)
Plus the existing localStorage/sessionStorage test, that's now 5
storage APIs covered — the full FR-026 list.

SC-012 "≥10 dedicated security tests":
Was 9, now 12. The 3 new storage tests above bring the dedicated
`describe('callAnthropicDirect — security: key never leaks')` block
above the floor. SC-012 verified.

Also fixed:
gradio-apps/compounding-test/deploy.sh:11-12 — usage comment block
still showed the old `./engine/scripts/deploy-hf-space.sh` path;
updated to the new path + added a --force example line
.specify/pr-body-draft.md — one-shot artifact for PR #36, removed
via `git rm` (PR body lives on GitHub now; no future reference
value in keeping a transient local copy)
specs/004-berkshire-test/plan.md — added "Amendment 2026-05-17"
footnote pointing at spec.md US5 so the design doc isn't silently
inconsistent with the amended spec (spec-coherence reviewer's
request)

Test counts:
npm test 946 passed, 1 skipped (was 943 → +3 storage tests)
npm run build clean
pytest 63 passed, 1 skipped (unchanged)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

deploy.sh

@@ -8,8 +8,9 @@
 #   # the remote name MUST be `hf-compounding-test` — this script looks for it
 #
 # Every deploy:
-#   ./engine/scripts/deploy-hf-space.sh           # push current branch
-#   ./engine/scripts/deploy-hf-space.sh --dry-run # sanity checks only
+#   ./gradio-apps/compounding-test/deploy.sh           # push current branch
+#   ./gradio-apps/compounding-test/deploy.sh --dry-run # sanity checks only
+#   ./gradio-apps/compounding-test/deploy.sh --force   # force-push (first deploy only)
 
 set -euo pipefail