Add EIP-6963 provider discovery

docs/browser-bridge.md

@@ -74,6 +74,15 @@ Unsupported methods return an EIP-1193-style error object with code `4200`.
 The injected provider also exposes `isConnected()`, `on`, and `removeListener` with a minimal event
 surface for `accountsChanged`, `chainChanged`, `connect`, and `disconnect`.
 
+## Provider discovery
+
+The injected provider supports EIP-6963 multi-wallet discovery in addition to the legacy
+`window.ethereum` path:
+
+- announces `eip6963:announceProvider` on page load
+- re-announces when the dapp dispatches `eip6963:requestProvider`
+- uses `name: "Deckard"`, `rdns: "com.deckard.wallet"`, and a self-contained SVG data URI icon
+
 `personal_sign`, `eth_sendTransaction`, broad signing, hardware wallets, native messaging, and store
 distribution are intentionally not implemented in this bridge slice. Kohaku remains useful for
 wallet-internal provider/backend integration, not as the browser-facing dapp provider.
@@ -195,7 +204,6 @@ Open <http://127.0.0.1:8777/> in the browser where the unpacked extension is loa
 
 - Decide native messaging vs hardened localhost using the PRD-04 spike evidence.
 - Add a real approval UI for `eth_requestAccounts` and per-origin revocation.
-- Add EIP-6963 provider announcement.
 - Persist permissions safely.
 - Consider a small integration test for the loopback `/rpc` HTTP boundary.
 - Add clear-signing/message-signing only after Deckard has the reviewed intent model for it.

extension/injected.js

@@ -2,6 +2,19 @@
   let nextId = 1;
   const pending = new Map();
   const listeners = new Map();
+  const deckardIconSvg = [
+    '<svg xmlns="http://www.w3.org/2000/svg" width="96" height="96" viewBox="0 0 96 96">',
+    '<rect width="96" height="96" rx="18" fill="#090b0b"/>',
+    '<path d="M28 22h20c16 0 28 11 28 26S64 74 48 74H28V22Zm14 13v26h6c8 0 14-5 14-13s-6-13-14-13h-6Z" fill="#f4d58d"/>',
+    '<circle cx="70" cy="26" r="7" fill="#4dd8d8"/>',
+    '</svg>',
+  ].join('');
+  const deckardProviderInfo = Object.freeze({
+    uuid: '3f2e4f7c-5e49-4d7d-8e2c-0d9a7c4f1193',
+    name: 'Deckard',
+    icon: `data:image/svg+xml,${encodeURIComponent(deckardIconSvg)}`,
+    rdns: 'com.deckard.wallet',
+  });
 
   class DeckardProvider {
     constructor() {
@@ -81,6 +94,18 @@
   }
 
   const provider = new DeckardProvider();
+  const providerDetail = Object.freeze({
+    info: deckardProviderInfo,
+    provider,
+  });
+
+  function announceProvider() {
+    window.dispatchEvent(
+      new CustomEvent('eip6963:announceProvider', {
+        detail: providerDetail,
+      }),
+    );
+  }
 
   window.addEventListener('message', (event) => {
     if (event.source !== window) return;
@@ -136,5 +161,7 @@
     configurable: true,
   });
 
+  window.addEventListener('eip6963:requestProvider', announceProvider);
+  announceProvider();
   window.dispatchEvent(new Event('ethereum#initialized'));
 })();

tests/extension/browser-bridge-extension.spec.ts

@@ -80,6 +80,61 @@ test('local dapp can connect through the injected provider', async ({ page }, te
   });
 });
 
+test('local dapp can discover Deckard through EIP-6963', async ({ page }) => {
+  await page.goto('/');
+  await expect(page.locator('#output')).toContainText('window.ethereum detected');
+
+  const discoveryState = await page.evaluate(async () => {
+    type Eip6963ProviderDetail = {
+      info: {
+        uuid: string;
+        name: string;
+        icon: string;
+        rdns: string;
+      };
+      provider: NonNullable<Window['ethereum']>;
+    };
+
+    const announcedProviders: Eip6963ProviderDetail[] = [];
+    window.addEventListener('eip6963:announceProvider', (event) => {
+      announcedProviders.push((event as CustomEvent<Eip6963ProviderDetail>).detail);
+    });
+    window.dispatchEvent(new Event('eip6963:requestProvider'));
+    await new Promise((resolve) => setTimeout(resolve, 0));
+
+    const detail = announcedProviders.find((providerDetail) => (
+      providerDetail.info.rdns === 'com.deckard.wallet'
+    ));
+    if (!detail) {
+      throw new Error('Deckard EIP-6963 provider announcement missing');
+    }
+
+    const chainId = await detail.provider.request({ method: 'eth_chainId' });
+    return {
+      announcementCount: announcedProviders.length,
+      detailFrozen: Object.isFrozen(detail),
+      infoFrozen: Object.isFrozen(detail.info),
+      sameProvider: detail.provider === window.ethereum,
+      chainId,
+      info: detail.info,
+    };
+  });
+
+  expect(discoveryState).toEqual({
+    announcementCount: 1,
+    detailFrozen: true,
+    infoFrozen: true,
+    sameProvider: true,
+    chainId: '0xaa36a7',
+    info: {
+      uuid: '3f2e4f7c-5e49-4d7d-8e2c-0d9a7c4f1193',
+      name: 'Deckard',
+      icon: expect.stringMatching(/^data:image\/svg\+xml,/),
+      rdns: 'com.deckard.wallet',
+    },
+  });
+});
+
 declare global {
   interface Window {
     ethereum?: {