fix: render the view "Back" lands on after the popup is reopened (closes #268)

TODO.md

@@ -59,6 +59,23 @@ undefined identifiers, which is how
   `tests/inpageErrors.test.js`, and the e2e probe that printed the missing code
   now requires it on the page's Error as well as on the wire, for all four
   rejected flows ([#274](https://git.eeqj.de/sneak/AutistMask/issues/274)).
+- 2026-08-12: "Back" now renders the screen it lands on instead of only unhiding
+  it. A reopened popup renders the wallet list and the one screen it restores
+  onto, so every screen further down the stack was still the blank template from
+  `index.html`, and Back walked straight onto it — an empty address, no
+  balances, no QR code. The Back path now goes through the same per-view
+  dispatch and data guards as the restore (`src/popup/viewRouter.js`, shared
+  with `restoreView()`), falling back to Home when the state the target would
+  render is gone. It renders only a view this page load has not rendered yet:
+  `viewRouter.js` records every view that reaches `showView()`, which is where
+  forward navigation and the restore both end, so Back onto a view already on
+  the page unhides it and nothing more. That is what keeps a second render from
+  re-fetching and overwriting what the view holds — an unsaved edit in Settings,
+  a transaction list already loaded. Home is the exception and is always
+  re-rendered, as it was before. Covered by unit tests on the real `goBack()`
+  and by three end-to-end cases against the real popup, each demonstrated
+  failing on the unfixed build
+  ([#268](https://git.eeqj.de/sneak/AutistMask/issues/268)).
 - 2026-08-12: `KNOWN_SYMBOLS` now maps a symbol to the set of contract addresses
   that bear it, not to one of them. A ticker is not unique: seven of the 512
   bundled tokens — `FRAX`, `REUSD`, `TON`, `EURE`, `MSUSD`, `MUSD` and `JPYC` —