docs: drop the README limit the EIP-1193 code fix removed (closes #285)

The End-to-End Tests section listed, as the third of three standing limits
of the dApp coverage, the EIP-1193 error code not surviving the last hop
into the page. That stopped being true when `9dcd875` landed
(#274): the provider now rejects
with a `ProviderRpcError` carrying `code`, and the e2e suite asserts the
code on the page as well as on the wire.

The other two limits are still accurate against the current code and are
left alone.

TODO.md

@@ -45,6 +45,15 @@ undefined identifiers, which is how
 
 # Completed Steps
 
+- 2026-08-17: `README.md` no longer advertises a defect the wallet does not
+  have. The End-to-End Tests section listed the EIP-1193 code being dropped in
+  the last hop into the page as a standing limit of the dApp coverage; that
+  stopped being true when
+  [#274](https://git.eeqj.de/sneak/AutistMask/issues/274) landed and did not
+  touch the README. The paragraph is deleted and the two remaining limits — the
+  stubbed RPC and the unobservable toolbar popup — were checked against the
+  current `src/content/inpage.js` and `tests/e2e/` and left as they are
+  ([#285](https://git.eeqj.de/sneak/AutistMask/issues/285)).
 - 2026-08-12: EIP-1193 error codes now reach the page. `src/content/inpage.js`
   rebuilt every failure as `new Error(error.message)`, so the code the
   background produced and the content script relayed intact was dropped in the