Add support for Unix socket with noauth

Problem: We're doing tons of unnecessary cryptography by encrypting the
connection between the "client" and "server", which are often running in
the same process.

Solution: Instead of connecting to the SSB service over TCP and
encrypting the stream, just connect over a socket (supported on Windows,
macOS, and Linux) and don't bother encrypting anything. This is what
Patchwork and Patchbay do already, and since our secret is at
`~/.ssb/secret` then we should be comfortable with `~/.ssb/socket` being
a trusted file where access implies authentication.

Local tests suggest that when sodium-native is available, this commit
reduces the time to render the 'Popular (Day)' page by 17%, but when we
have to fall back to JavaScript cryptography the same page now takes 30%
less time to render. My intuition is that this improvement is more
dramatic on mobile, but requires further testing before we can pat
ourselves on the back too much. :)

.cspell.json

@@ -28,6 +28,7 @@
     "multiserver",
     "muxrpc",
     "nanohtml",
+    "noauth",
     "nosniff",
     "paramap",
     "patchbay",

src/ssb.js

@@ -10,6 +10,16 @@ const ssbConfig = require("ssb-config");
 const flotilla = require("@fraction/flotilla");
 const ssbTangle = require("ssb-tangle");
 const debug = require("debug")("oasis");
+const path = require("path");
+
+const socketPath = path.join(ssbConfig.path, "socket");
+const publicInteger = ssbConfig.keys.public.replace(".ed25519", "");
+const remote = `unix:${socketPath}~noauth:${publicInteger}`;
+
+// This is unnecessary when https://github.com/ssbc/ssb-config/pull/72 is merged
+ssbConfig.connections.incoming.unix = [
+  { scope: "device", transform: "noauth" }
+];
 
 const server = flotilla(ssbConfig);
 
@@ -22,7 +32,7 @@ const log = (...args) => {
 
 const rawConnect = () =>
   new Promise((resolve, reject) => {
-    ssbClient()
+    ssbClient(null, { remote })
       .then(api => {
         if (api.tangle === undefined) {
           // HACK: SSB-Tangle isn't available in Patchwork, but we want that
@@ -64,7 +74,9 @@ const createConnection = config => {
               resolve(ssb);
             })
             .catch(e => {
-              log(e);
+              if (e.message !== "could not connect to sbot") {
+                log(e);
+              }
               connectOrRetry();
             });
         };