🐛 Raise default binfile import text total to 500MiB

Giant legitimate exports hold hundreds of MB of JSON across
hundreds of thousands of KB-sized entries without tripping any
per-entry cap, so the 200MiB cumulative default rejected them out
of the box. Raise it to 500MiB; the 20MiB per-entry cap still
bounds single-entry inflation. Pin the floor with a regression
test.

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

backend/src/app/binfile/common.clj

@@ -68,11 +68,15 @@
   (* 1024 1024 20))
 
 ;; Maximum total decompressed size allowed for all JSON/text zip entries
-;; combined within a single import job: 200MiB. Bounds the case where many
+;; combined within a single import job: 500MiB. Bounds the case where many
 ;; entries, each individually under default-max-text-entry-size, still sum
-;; to an unreasonable total.
+;; to an unreasonable total. Set well above the 200MiB it replaces because
+;; legitimate giant exports exist: hundreds of thousands of KB-sized
+;; entries (pages, shapes) that never trip the per-entry cap but sum past
+;; 400MiB. The per-entry cap still bounds single-entry DEFLATE
+;; amplification, so this only moves the cumulative ceiling.
 (def ^:const default-max-text-total-size
-  (* 1024 1024 200))
+  (* 1024 1024 500))
 
 ;; Maximum number of entries allowed in the import zip: 500,000.
 (def ^:const default-max-zip-entries

backend/test/backend_tests/binfile_test.clj

@@ -2153,6 +2153,13 @@
       (t/is (= :validation (:type out)))
       (t/is (= :max-file-size-reached (:code out))))))
 
+(t/deftest default-text-total-budget-fits-giant-legit-files
+  ;; A real-world giant export held ~437 MiB of JSON across ~178k
+  ;; KB-sized entries without tripping any per-entry cap. The default
+  ;; cumulative budget must clear that scale, or such files cannot be
+  ;; imported out of the box.
+  (t/is (>= bfc/default-max-text-total-size (* 1024 1024 450))))
+
 (defn- text-entries-sizes
   "Returns the decompressed sizes of every `.json` entry in the zip at
   `zip-path`. Used to pick a cumulative budget that sits between the