test: load the popup's libraries once per test file, not on every boot (closes #428)

Every popup boot in the tests resets jest's module registry so that src/
loads fresh, and that also reloaded ethers, libsodium-wrappers-sumo, qrcode
and ethereum-blockies-base64 each time: more than half of a boot, and
tests/persistedFieldContract.test.js boots the popup 321 times.
tests/support/popupBoot.js now loads those four once per test file and hands
the same copies to every boot. No test or assertion changed. make test takes
10-15s on the shared build host instead of 23-29s.

Model: opus-5-5

TODO.md

@@ -45,6 +45,15 @@ but the review is broader than any of them.
 
 # Completed Steps
 
+- 2026-10-04: `make test` takes 10-15s on the shared build host, down from
+  23-29s ([#428](https://git.eeqj.de/sneak/AutistMask/issues/428)). Each popup
+  boot in the tests (`tests/support/popupBoot.js`) resets jest's module registry
+  so that everything under `src/` loads fresh, and that also reloaded `ethers`,
+  `libsodium-wrappers-sumo`, `qrcode` and `ethereum-blockies-base64` every time:
+  more than half of each boot, and `tests/persistedFieldContract.test.js` boots
+  the popup 321 times. Those four libraries are now loaded once per test file
+  and handed to every boot. No test or assertion changed.
+
 - 2026-10-04: `make test` runs jest in three worker processes
   ([#426](https://git.eeqj.de/sneak/AutistMask/issues/426)). The `test` and
   `test:verbose` scripts in `package.json` ran `jest --forceExit`, which starts