diff --git a/.serena/memories/backend/testing.md b/.serena/memories/backend/testing.md
index 23ae25c31c..256a330fa1 100644
--- a/.serena/memories/backend/testing.md
+++ b/.serena/memories/backend/testing.md
@@ -5,6 +5,7 @@ JVM `clojure.test` (kaocha runner) under `backend/test/backend_tests/`.
 - READ `mem:testing` FIRST — it defines the execution discipline (no piping, tee to file, preferred commands) that applies to all JVM test runs.
 - All CLI commands must be executed from the `backend/` subdirectory.
 - Tests are invoked directly via `clojure -M:dev:test` (kaocha) — there is no pnpm wrapper. Kaocha auto-discovers test namespaces, so no runner registration is needed.
+- `clojure.core/assert` is elided at compile time unless `PENPOT_FLAGS` contains `enable-backend-asserts` (`app.config` sets `*assert*` from it). `scripts/ci` and `tests-backend.yml` export the flag; a bare `clojure -M:dev:test` (or `--focus` run) without it silently skips every precondition assert.
 - Coverage: if code is added or modified in `src/`, corresponding tests in `test/backend_tests/` must be added or updated.
 - Isolated run: `clojure -M:dev:test --focus backend-tests.my-ns-test` for a specific test namespace, or `clojure -M:dev:test --focus backend-tests.my-ns-test/my-test-var` for a specific test var.
 - Regression run: `clojure -M:dev:test` to ensure no regressions in related functional areas.
diff --git a/.serena/memories/scripts/ci.md b/.serena/memories/scripts/ci.md
index 69d3fa6968..e3ee25c614 100644
--- a/.serena/memories/scripts/ci.md
+++ b/.serena/memories/scripts/ci.md
@@ -55,6 +55,9 @@ Flags:
 
 - `mcp` has no lint task (shows as skipped). `render-wasm` uses `./lint`,
   `./test`, and `cargo fmt`.
+- Exports `PENPOT_FLAGS` with `enable-backend-asserts` appended to any
+  existing value, so backend test runs compile in and exercise
+  precondition asserts; see `mem:backend/testing`.
 - Test tasks are long-running (backend: `clojure -M:dev:test`); use a
   generous timeout when calling it from an agent shell.
 - Skill entry point: `.agents/skills/local-ci/SKILL.md`.
diff --git a/backend/test/backend_tests/binfile_svg_test.clj b/backend/test/backend_tests/binfile_svg_test.clj
index 500c497df1..a12d30e895 100644
--- a/backend/test/backend_tests/binfile_svg_test.clj
+++ b/backend/test/backend_tests/binfile_svg_test.clj
@@ -256,6 +256,7 @@
           result (-> th/*system*
                      (assoc ::bfc/project-id (:default-project-id profile))
                      (assoc ::bfc/profile-id (:id profile))
+                     (assoc ::bfc/team-id (:default-team-id profile))
                      (assoc ::bfc/input evil)
                      (v3/import-files!))]
       (t/is (= 1 (count (:file-ids result))))
diff --git a/backend/test/backend_tests/binfile_test.clj b/backend/test/backend_tests/binfile_test.clj
index df12541d16..b29b2fcf29 100644
--- a/backend/test/backend_tests/binfile_test.clj
+++ b/backend/test/backend_tests/binfile_test.clj
@@ -180,6 +180,7 @@
     (let [result (-> th/*system*
                      (assoc ::bfc/project-id (:default-project-id profile))
                      (assoc ::bfc/profile-id (:id profile))
+                     (assoc ::bfc/team-id (:default-team-id profile))
                      (assoc ::bfc/input output)
                      (v3/import-files!))
           file-id  (first (:file-ids result))
@@ -213,6 +214,7 @@
         result (-> th/*system*
                    (assoc ::bfc/project-id (:default-project-id profile))
                    (assoc ::bfc/profile-id (:id profile))
+                   (assoc ::bfc/team-id (:default-team-id profile))
                    (assoc ::bfc/input input)
                    (v3/import-files!))]
     (bfc/get-file th/*system* (first (:file-ids result)))))
@@ -267,6 +269,7 @@
     (let [result (-> th/*system*
                      (assoc ::bfc/project-id (:default-project-id profile))
                      (assoc ::bfc/profile-id (:id profile))
+                     (assoc ::bfc/team-id (:default-team-id profile))
                      (assoc ::bfc/input output)
                      (v3/import-files!))]
       (t/is (map? result))
@@ -300,6 +303,7 @@
     (let [result   (-> th/*system*
                        (assoc ::bfc/project-id (:default-project-id profile))
                        (assoc ::bfc/profile-id (:id profile))
+                       (assoc ::bfc/team-id (:default-team-id profile))
                        (assoc ::bfc/input output)
                        (v3/import-files!))
           imported (bfc/get-file th/*system* (first (:file-ids result)))]
@@ -2388,6 +2392,7 @@
     (let [result (:file-ids (-> th/*system*
                                 (assoc ::bfc/project-id (:default-project-id profile))
                                 (assoc ::bfc/profile-id (:id profile))
+                                (assoc ::bfc/team-id (:default-team-id profile))
                                 (assoc ::bfc/input output)
                                 (v3/import-files!)))
           files  (map #(bfc/get-file th/*system* %) result)
@@ -2466,6 +2471,7 @@
     (let [result  (:file-ids (-> th/*system*
                                  (assoc ::bfc/project-id (:default-project-id profile))
                                  (assoc ::bfc/profile-id (:id profile))
+                                 (assoc ::bfc/team-id (:default-team-id profile))
                                  (assoc ::bfc/input output)
                                  (v3/import-files!)))
           mobjs   (db/query th/*system* :file-media-object