fix(ci): classify release-tools in the coverage policy (#1260)

#1256 added the release-tools project with a test target but never listed it
in tools/coverage/coverage-policy.json, so `coverage:ci` fails with "Coverage
policy is missing projects that have a test target: - release-tools". Master
has been red since that merge (270350c2) and every PR rebased onto it inherits
the failure.

Tier B, mirroring the sibling `packaging` project: the tests validate
release-note parsing, rendering and gate policy, but the scripts are release
tooling rather than shipped source, so a percentage-coverage baseline would
measure nothing useful.

Verified: `check-coverage-policy.mjs` reports 36 projects classified
(30 A / 6 B / 6 C), and `--run-non-tier-a` runs the release-tools suite green.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

tools/coverage/coverage-policy.json

@@ -233,6 +233,12 @@
                 "validationCommand": "pnpm nx test packaging",
                 "reason": "Node package identity checks validate generated packaging metadata."
             },
+            {
+                "name": "release-tools",
+                "root": "tools/release",
+                "validationCommand": "pnpm nx test release-tools",
+                "reason": "Node tests validate release-note parsing, rendering and gate policy; the scripts are release tooling, not shipped source."
+            },
             {
                 "name": "remote-control-web",
                 "root": "apps/remote-control-web",