Booleans are deterministic: result faces keep their shell's order

truck's connected components came out in hash order of face addresses, so a
boolean's faces, and everything built on them (fillet bands, STEP entity
order), changed from run to run. That made the oracle 35 export differ run to
run. Its old step_export flakes came from the orientation check's drifting
search, removed in 2db9e66. The result's shells and faces now keep the
order of the shell they come from (vendored truck-shapeops). Oracle results
are unchanged (73 PASS before and after). Test: the tee of oracle 35 with its
junction fillet exports byte-identical three times in one process (it failed
before).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

vendor/README.md

@@ -11,6 +11,9 @@ Changes:
   earlier booleans have boundaries that lie on their surface only within tolerance).
 - `transversal/divide_face/mod.rs`: when projecting a loop onto a face's surface, fall back to
   the nearest parameter when the exact search fails (intersection curves are approximations).
+- `transversal/integrate/mod.rs`: the result's shells and faces keep the order of the shell
+  they come from (truck's connected components followed hash order of face addresses, so a
+  boolean's faces came out in a different order on every run).
 - `lib.rs`: `tr!` reports where an operation gives up when `SHAPEOPS_TRACE` is set; compiler
   warnings no longer fail the build.