fix(engine): the affirmative TAGS-SIGNED was suppressed by its own exemption OK

Gated on `findings.length === 0`, so a TAG-SIGNED-PREPOLICY OK silenced it —
and every repo in the org has pre-policy tags, which made the affirmative
verdict near-unreachable in practice.

Caught by dogfooding v0.11.0: this repo signed the first tag the check ever
judged, and the gate did not say so. Status was green either way, which is
exactly why it was worth fixing — a reader could not tell "signed its new tag"
from "has cut no tag since the policy". Two different facts wearing one
silence, which is the defect this engine already refuses to ship one check
over, where an exemption nobody can see reads like a check that stopped
running.

Keys the affirmative on the JUDGED findings only. Measured after: 18 repos
emit both codes, 3 NONE, still 0 ERROR / 0 WARN. 243 tests, from 241.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XsPsVsvhrSaejK3cLPmnN2

.claude-plugin/plugin.json

@@ -1,6 +1,6 @@
 {
   "name": "repo-standard",
-  "version": "0.11.0",
+  "version": "0.11.1",
   "description": "Per-repo gate for the open/ presentation standard: README first screen, install block, files required by the repo's class, and dead repo references.",
   "author": {
     "name": "Kjell Tore Guttormsen"