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.html

@@ -1761,6 +1761,75 @@
                     </button>
                 </div>
             </div>
+
+            <!-- ============ STATE RECOVERY ============ -->
+            <!--
+                Shown when the stored profile cannot be read at all. Every
+                other screen renders from that profile, so this one is reached
+                without one and is the only way out of a wallet that would
+                otherwise be a blank popup.
+            -->
+            <div id="view-state-recovery" class="view hidden">
+                <h2 class="font-bold mb-2">Saved Data Cannot Be Read</h2>
+                <p class="text-xs mb-2">
+                    AutistMask stopped rather than guessing. Nothing has been
+                    changed or erased, and nothing can be signed or sent until
+                    this is resolved.
+                </p>
+                <div
+                    id="state-recovery-problem"
+                    class="text-xs font-bold mb-3 break-words"
+                ></div>
+                <p class="text-xs mb-2">
+                    Export the saved data first and keep it. It may hold the
+                    encrypted keys for your wallets, and it is the only copy.
+                </p>
+                <button
+                    id="btn-state-recovery-export"
+                    class="border border-border px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                >
+                    Export Saved Data
+                </button>
+                <textarea
+                    id="state-recovery-blob"
+                    readonly
+                    class="hidden border border-border p-1 w-full h-32 font-mono text-xs bg-bg text-fg mt-2"
+                ></textarea>
+                <p class="text-xs mt-3 mb-2">
+                    <strong
+                        >Erasing the saved data deletes every wallet stored in
+                        this browser.</strong
+                    >
+                    Nothing on the blockchain changes and no money is moved, but
+                    without the exported copy above, or the recovery phrase for
+                    each wallet written down, everything they hold is gone
+                    forever.
+                </p>
+                <p class="text-xs mb-1">
+                    To confirm, type
+                    <strong>ERASE MY WALLET</strong>
+                    below.
+                </p>
+                <div class="mb-2">
+                    <input
+                        type="text"
+                        id="state-recovery-reset-input"
+                        class="border border-border p-1 w-full font-mono text-sm bg-bg text-fg"
+                        placeholder="Type ERASE MY WALLET"
+                    />
+                </div>
+                <div
+                    id="state-recovery-flash"
+                    class="text-xs text-red-500 mb-2 min-h-[1.25rem]"
+                    style="visibility: hidden"
+                ></div>
+                <button
+                    id="btn-state-recovery-reset"
+                    class="border border-border text-red-500 px-2 py-1 hover:bg-fg hover:text-bg cursor-pointer"
+                >
+                    Erase Saved Data
+                </button>
+            </div>
         </div>
 
         <script src="index.js"></script>