ci(ci): add SRS_ADMIN_KEY env var and documentation to CI workflows

.github/workflows/close-solved.yml

@@ -28,7 +28,14 @@ jobs:
       - uses: oven-sh/setup-bun@v2
 
       # No install step: the script only uses Bun builtins + fetch.
+      #
+      # SRS_ADMIN_KEY lets the script report the solved set to the Worker
+      # (POST /admin/solved). Closing an issue is invisible to D1 — the
+      # catalog reconcile never reads issue state, and only logAttempt() moves
+      # the ladder — so without this a pushed solution would never reach the
+      # charts, the digest's solved ticks, or the drill/gate pools.
       - run: bun apps/cli/close-solved.ts
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           DRY_RUN: ${{ inputs.dry_run }}
+          SRS_ADMIN_KEY: ${{ secrets.SRS_ADMIN_KEY }}

.github/workflows/close-topics.yml

@@ -1,5 +1,10 @@
 name: Close Topics
 
+# No D1 push here, unlike Close Solved: D1 stores no topic completion column.
+# Phase progress, the gate pools and the charts all derive from the problem
+# rows, which close-solved already logs — a topic is finished exactly when its
+# core problems are, so there is nothing left to reconcile.
+
 on:
   # Close Solved closes problem issues with GITHUB_TOKEN, and token-driven
   # closes never fire `issues` events — so chain off its run instead.