🐛 Add concurrency limit to import-binfile RPC handler

Apply climit with 4 global permits and 1 per-profile permit (queue 2)
to prevent connection pool exhaustion from concurrent imports. Each
import holds a DB connection for its entire duration with idle
transaction timeout disabled, so unbounded concurrency could exhaust
the pool (default 60 connections).

AI-assisted-by: mimo-v2.5

backend/resources/climit.edn

@@ -38,5 +38,11 @@
  :create-file-snapshot/global
  {:permits 3}
 
- :create-file-snapshot/by-profile
- {:permits 1 :queue 2 :timeout 60000}}
+:create-file-snapshot/by-profile
+{:permits 1 :queue 2 :timeout 60000}
+
+:import-binfile/global
+{:permits 4}
+
+:import-binfile/by-profile
+{:permits 1 :queue 2}}

backend/src/app/rpc/commands/binfile.clj

@@ -21,6 +21,7 @@
    [app.loggers.webhooks :as-alias webhooks]
    [app.media :as media]
    [app.rpc :as-alias rpc]
+   [app.rpc.climit :as-alias climit]
    [app.rpc.commands.files :as files]
    [app.rpc.commands.media :as media-cmd]
    [app.rpc.commands.projects :as projects]
@@ -144,7 +145,9 @@
 
    ::webhooks/event? true
    ::sse/stream? true
-   ::sm/params schema:import-binfile}
+   ::sm/params schema:import-binfile
+   ::climit/id [[:import-binfile/by-profile ::rpc/profile-id]
+                [:import-binfile/global]]}
   [{:keys [::db/pool] :as cfg} {:keys [::rpc/profile-id project-id version upload-id] :as params}]
   (projects/check-edition-permissions! pool profile-id project-id)
   (let [version (or version 3)

backend/test/backend_tests/rpc_binfile_test.clj

@@ -9,6 +9,7 @@
    [app.common.schema :as sm]
    [app.common.uuid :as uuid]
    [app.rpc :as-alias rpc]
+   [app.rpc.climit :as-alias climit]
    [app.rpc.commands.binfile :as binfile]
    [backend-tests.helpers :as th]
    [clojure.test :as t]
@@ -40,3 +41,10 @@
     ;; (Currently this will fail because file-id is still in schema)
     (t/is (false? (validator params-with-file-id))
           "params with file-id should be rejected")))
+
+(t/deftest import-binfile-has-concurrency-limit
+  ;; N1-10: import-binfile must have a concurrency limit to prevent
+  ;; connection pool exhaustion from concurrent imports
+  (let [mdata (meta #'binfile/sm$import-binfile)]
+    (t/is (some? (::climit/id mdata))
+          "import-binfile must have ::climit/id metadata")))