♻️ Name the temp-file boot clean for what it does

`app.jobs.utils/init` initialized nothing: its only work was the
boot-time sweep of temp files a crashed process left behind. It is
now the public `clean-orphans`, with a docstring that says it runs
once at boot, and `app.core` calls it by that name.

AI-assisted-by: muse-spark-1.3-contributor

exporter/src/app/core.cljs

@@ -40,7 +40,7 @@
               :image-cache-size (cf/get :wasm-worker-image-cache-size))
       (p/do
         (bwr/init)
-        (job.utils/init)
+        (job.utils/clean-orphans)
         (wasm.pool/init)
         (worker/start)))))
 

exporter/src/app/jobs/utils.cljs

@@ -53,9 +53,10 @@
                      nil)))
       (p/resolved nil))))
 
-(defn- clean
+(defn clean-orphans
   "Removes managed temp files older than the job TTL. They can only be leftovers
-  of a previous process: every live one belongs to a job of this process."
+  of a previous process: every live one belongs to a job of this process.
+  Runs once at boot; nothing here needs initializing."
   []
   (let [max-age (* 1000 (cf/get :exporter-job-ttl 3600))
         now     (js/Date.now)]
@@ -80,7 +81,3 @@
          (p/merr (fn [cause]
                    (l/warn :hint "temp file cleanup failed" :cause cause)
                    (p/resolved 0))))))
-
-(defn init
-  []
-  (clean))