fix: closing a transaction or signature approval window leaves the request pending (closes #673)

Closing a transaction or signature approval window no longer rejects the request; only Cancel does. The browser can close that window when the user clicks away, for example to copy the password from a password manager. The request stays pending and the site gets no answer. Pressing the toolbar button opens the oldest such request, unless an approved attempt still holds it. A Reject the background refuses keeps the window open with the background's message. The worker points the toolbar back at the wallet when it starts.

While such a request waits, the transaction slot stays held, so another site's eth_sendTransaction gets -32002. An address switch still rejects pending approvals with 4001.

Model: opus-5-5

README.md

@@ -512,7 +512,10 @@ window of its own, and the password is required to be absent from every message
 the approval window sends to the background — with the message that would carry
 it required to be present, so that check cannot pass by observing nothing. That
 last one is the standing floor under
-[#157](https://git.eeqj.de/sneak/AutistMask/issues/157).
+[#157](https://git.eeqj.de/sneak/AutistMask/issues/157). Closing a transaction
+or signature approval window is required to leave the dApp's request unanswered.
+The suite then opens that approval at the URL the toolbar button holds, and
+answers it there.
 
 The limits of that coverage and of the rest of the Chrome suite, none of them
 papered over:
@@ -521,9 +524,9 @@ papered over:
   network with real funds; that remains a human pass before 1.0.0.
 - The site-connection prompt is raised through `chrome.action.openPopup()`, and
   headless Chromium's browser-action popup is not a page Playwright can see or
-  click, so that one prompt is driven at the URL the extension itself puts on
-  the action — the same page and the same approval id, but whether a real
-  toolbar click shows it is not observable here.
+  click. So that prompt, and an approval reopened after its window closed, are
+  opened in a tab at the URL the extension puts on the action. Whether a real
+  toolbar click shows that page is not observable here.
 - Each site-connection request is made 1.5 seconds after the tab it will be
   driven in is opened (`APPROVAL_TAB_SETTLE_MS` in `tests/e2e/run.js`), because
   opening that tab closes the previous prompt's toolbar popup; a request made
@@ -642,15 +645,24 @@ above, it does not fail on page errors.
 
 `make test-e2e-firefox` builds `dist/firefox/` and drives the **real popup in a
 real Firefox**, installed as an unpacked MV2 temporary add-on via geckodriver.
-It covers popup load, the StateRecovery screen (the same cases as the Chrome
-suite), wallet creation through the UI, the Add Token screen, and the dApp round
-trips — `eth_requestAccounts`, `personal_sign`, `wallet_switchEthereumChain`
-rejected and then approved, `eth_sendTransaction`, and a closed approval window
-rejecting with EIP-1193 4001 — driven through the real content script,
-background page and approval windows. The popup open all along is required to
-show the `[TESTNET]` banner once the switch to Sepolia is approved and to drop
-it once the switch back is. The `personal_sign` prompt is also required to fit
-its window without scrolling sideways, with the extension's pages at 170% zoom.
+It covers:
+
+- popup load
+- the StateRecovery screen, with the same cases as the Chrome suite
+- wallet creation through the UI
+- the Add Token screen
+- `eth_requestAccounts` from a dApp
+- `personal_sign` from a dApp
+- `wallet_switchEthereumChain` from a dApp, rejected and then approved
+- `eth_sendTransaction` from a dApp
+- an approval window closed without an answer, which leaves its request pending
+  until it is rejected
+
+Each dApp request runs through the real content script and background page, and
+opens a real approval window. The popup open all along is required to show the
+`[TESTNET]` banner once the switch to Sepolia is approved and to drop it once
+the switch back is. The `personal_sign` prompt is also required to fit its
+window without scrolling sideways, with the extension's pages at 170% zoom.
 
 The suite lives in `tests/e2e/firefox/`. Its WebDriver client (`driver.js`) has
 **no npm dependencies at all**: it is built on global `fetch` and
@@ -2644,8 +2656,14 @@ view would leave a wallet one click from deletion.
       Data Model) → full-sentence error on the error line saying why, nothing
       signed (no screen change)
     - "Reject" → closes popup (returns rejection to background)
-    - Popup window closed without answering → the request is rejected with
-      EIP-1193 code 4001
+    - "Reject" after "Confirm", while the transaction is being sent → the
+      background's message on the error line, no screen change
+    - Popup window closed without answering → the request stays pending, and the
+      site gets no answer. The browser can close this window when the user
+      clicks away from it, for example to copy the password from a password
+      manager. Until the request is answered, the toolbar button opens this
+      screen instead of the wallet. When several requests wait with their
+      windows closed, the toolbar button opens the oldest first.
 
 #### SignApproval (`approve-sign`)
 
@@ -2734,8 +2752,11 @@ view would leave a wallet one click from deletion.
     - "Sign" (wrong password, or a signing failure) → error line, no screen
       change
     - "Reject" → closes popup (returns rejection to background)
-    - Popup window closed without answering → the request is rejected with
-      EIP-1193 code 4001
+    - "Reject" after "Sign", while the signature is being checked → the
+      background's message on the error line, no screen change
+    - Popup window closed without answering → the request stays pending, as on
+      TxApproval. Until the request is answered, the toolbar button opens this
+      screen instead of the wallet.
 
 #### NetworkApproval (`approve-network`)