fix: version stored state, validate its shape, and give a corrupt blob a way out (closes #311)

Stored state had no version and no structural validation, so a corrupt blob produced a completely blank popup with no message and no recovery control, and made every dApp RPC call from every page answer a generic -32603. There was no reset or wipe control anywhere in the UI.

saveState() now stamps a schema version and loadState() validates the shape. A version it does not understand, or a wallets array it cannot parse, lands on a recovery screen that names the problem, offers the stored record verbatim for export, and offers a destructive reset behind a typed confirmation. Unversioned but valid state -- which every existing install has -- migrates in place and keeps working; it is never shown a wipe prompt. A dApp call against unusable state answers -32007, which EIP-1474 leaves unassigned, rather than -32603. networkById() refuses an unknown id loudly instead of returning mainnet, and networkId is validated so a corrupt value cannot be used as an object key.

Fields the gate does not refuse are floored by type, container and entries both: a malformed trackedTokens or tokenBalances entry is dropped rather than dereferenced. Verified by an independent sweep of 1152 corrupt blobs producing no blank popup, with the same harness showing 9 blanks against the previous revision.

src/popup/index.js

@@ -2,6 +2,7 @@
 // Loads state, initializes views, triggers first render.
 
 const { state, saveState, loadState } = require("../shared/state");
+const { StateUnusableError } = require("../shared/stateSchema");
 const { setRuntimeDebug } = require("../shared/log");
 const { refreshPrices } = require("../shared/prices");
 const { refreshBalances } = require("../shared/balances");
@@ -16,7 +17,7 @@ const {
 const { applyTheme } = require("./theme");
 // Renders a view the popup lands on without having navigated to it forward:
 // on restore here, and on Back. Only the views that can be fully re-rendered
-// from persisted state (RESTORABLE_VIEWS, src/popup/restorableViews.js) go
+// from persisted state (RESTORABLE_VIEWS, src/shared/restorableViews.js) go
 // through it; anything else falls back to the nearest restorable parent.
 const { renderView, makeBackRenderer } = require("./viewRouter");
 
@@ -35,6 +36,7 @@ const settings = require("./views/settings");
 const settingsAddToken = require("./views/settingsAddToken");
 const deleteAddress = require("./views/deleteAddress");
 const approval = require("./views/approval");
+const stateRecovery = require("./views/stateRecovery");
 
 function renderWalletList() {
     home.render(ctx);
@@ -134,7 +136,22 @@ function fallbackView() {
 }
 
 async function init() {
-    await loadState();
+    try {
+        await loadState();
+    } catch (e) {
+        // A profile this build cannot read is the one failure that must not
+        // fall through to the rest of init(). It used to: the load "succeeded"
+        // on a record nothing had validated, and the first dereference below
+        // threw, leaving a popup with no view, no message and no control on
+        // it, and no way out of the wallet from inside the product
+        // (https://git.eeqj.de/sneak/AutistMask/issues/311). Now the load
+        // refuses, and this is the screen that says so.
+        if (e instanceof StateUnusableError) {
+            stateRecovery.show(e);
+            return;
+        }
+        throw e;
+    }
     applyTheme(state.theme);
 
     // Sync runtime debug flag from persisted state before first render