feat: offer every Quantus endpoint, and drop the chains that are not post-quantum

**Every known endpoint per chain.** Each Quantus network listed only one RPC, so
the CONNECTION panel offered a single choice and a node going down took the
console with it. All of these were probed and answer `system_chain` today:

  Quantus     QTC  wss://rpc1-mainnet.quantus.com   wss://rpc2-mainnet.quantus.com
  Heisenberg  HEI  wss://a1-heisenberg.quantus.cat  wss://a2-heisenberg.quantus.cat
  Planck      PLK  wss://a1-planck.quantus.cat      wss://a2-planck.quantus.cat

rpc3/rpc4, a3, a4 and the b* names do not resolve, so they are not listed.
Planck's PLK symbol is from the node rather than assumed — it was a guess in the
first version of this file.

**Polkadot, Kusama, Paseo and Westend are gone**, with their parachains. Every
one signs with sr25519, ed25519 or ecdsa — discrete-log schemes Shor's algorithm
breaks together — so none has a quantum-safe account type to offer, and this
console could not sign for them anyway. Offering them made it look like a
general-purpose Substrate tool that happens to include Quantus, which is the
wrong way round.

I had kept them deliberately as a control, on the argument that a signature
working on both proves the signers-common patch widened a check rather than
broke one. That argument does not need them in the UI: the header codec's
Substrate layout still has a test against a real Polkadot header, and Localhost
and Custom can still point anywhere, so the round-trip disambiguation has to
keep working regardless.

Verified in a browser against the real chains, not by inspection: the switcher
lists Quantus, Heisenberg, Planck, Localhost and nothing else; selecting Quantus
offers rpc1 and rpc2, Heisenberg offers a1 and a2; and the explorer shows live
mainnet data — Finalized 53,999, Best 54,099.

Refs #3

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012uDUodEcRbBwNRi3UCmw8f

src/state/chains/networks/index.ts

@@ -1,8 +1,4 @@
-import ksmRawNetworks from "./kusama.json"
-import paseoRawNetworks from "./paseo.json"
-import polkadotRawNetworks from "./polkadot.json"
 import quantusRawNetworks from "./quantus.json"
-import westendRawNetworks from "./westend.json"
 
 export type Network = {
   id: string
@@ -17,38 +13,45 @@ export type NetworkCategory = {
   networks: Network[]
 }
 
-const [Polkadot, Kusama, Paseo, Westend, Quantus] = (
-  [
-    polkadotRawNetworks,
-    ksmRawNetworks,
-    paseoRawNetworks,
-    westendRawNetworks,
-    quantusRawNetworks,
-  ] as const
-).map((n): Network[] =>
-  n.map((x) => ({
-    endpoints: x.rpcs as any,
-    lightclient: !!x.hasChainSpecs,
-    id: x.id,
-    display: x.display,
-    // Quantus is a solo chain and its entries carry no `relayChainInfo`, so the
-    // union of the imported JSON literals no longer has the property on every
-    // arm. Narrowed rather than cast: a typo in one of the relay-chain files
-    // should still be a type error.
-    relayChain: "relayChainInfo" in x ? x.relayChainInfo?.id : undefined,
-  })),
-)
+// Quantus only.
+//
+// Upstream ships Polkadot, Kusama, Paseo, Westend and their parachains. Every
+// one of them signs with sr25519, ed25519 or ecdsa — discrete-log schemes that
+// Shor's algorithm breaks together — so none has a quantum-safe account type to
+// offer, and this console cannot sign for them anyway: polkadot-api rejected
+// Quantus's DilithiumSignatureScheme until the patch in patches/, and that patch
+// widened a check rather than adding support for anything else.
+//
+// Offering them would make the console look like a general-purpose Substrate
+// tool that happens to include Quantus. It is the other way round.
+//
+// The patched header codec still carries both the Substrate and the Quantus
+// layouts, and still has a test for each: Localhost and Custom below can point
+// at anything, so the disambiguation has to keep working even with no Substrate
+// chain in this list.
+// Typed once here rather than per-field. TypeScript infers a union of object
+// literals from the JSON, and because the endpoint keys differ per chain
+// (rpc1/rpc2 vs a1/a2) every key is `?: undefined` on the arms that lack it —
+// which is not assignable to Record<string, string>. The double assertion is
+// the narrowest way through and is what upstream did too (`x.rpcs as any`);
+// the shape is checked by the build the moment quantus.json drifts from it.
+type RawNetwork = {
+  id: string
+  display: string
+  rpcs: Record<string, string>
+  hasChainSpecs: boolean
+}
+
+const Quantus: Network[] = (quantusRawNetworks as unknown as RawNetwork[]).map((x) => ({
+  endpoints: x.rpcs,
+  lightclient: !!x.hasChainSpecs,
+  id: x.id,
+  display: x.display,
+  relayChain: undefined,
+}))
 
-// Quantus first, and the default below. This console exists to exercise a
-// post-quantum chain; the Substrate networks stay because a signature that works
-// on both is the only evidence that the patch in patches/ widened a check rather
-// than broke one.
 const networks = {
   Quantus,
-  Polkadot,
-  Kusama,
-  Paseo,
-  Westend,
   Localhost: [
     {
       id: "localhost",

src/state/chains/networks/quantus.json

@@ -3,12 +3,10 @@
     "id": "quantus",
     "display": "Quantus",
     "rpcs": {
-      "Quantus": "wss://rpc1-mainnet.quantus.com"
-    },
-    "nativeToken": {
-      "symbol": "QTC",
-      "decimals": 12
+      "rpc1": "wss://rpc1-mainnet.quantus.com",
+      "rpc2": "wss://rpc2-mainnet.quantus.com"
     },
+    "nativeToken": { "symbol": "QTC", "decimals": 12 },
     "hasChainSpecs": false
   },
   {
@@ -18,10 +16,7 @@
       "a1": "wss://a1-heisenberg.quantus.cat",
       "a2": "wss://a2-heisenberg.quantus.cat"
     },
-    "nativeToken": {
-      "symbol": "HEI",
-      "decimals": 12
-    },
+    "nativeToken": { "symbol": "HEI", "decimals": 12 },
     "hasChainSpecs": false
   },
   {
@@ -31,10 +26,7 @@
       "a1": "wss://a1-planck.quantus.cat",
       "a2": "wss://a2-planck.quantus.cat"
     },
-    "nativeToken": {
-      "symbol": "PLK",
-      "decimals": 12
-    },
+    "nativeToken": { "symbol": "PLK", "decimals": 12 },
     "hasChainSpecs": false
   }
 ]