Add yaw2 invite interoperability

Protocol:
- invite.go: include full 64-char `net` hash in waste: invite blob
  (matches yaw2's `net` field — any client parsing the base64 JSON can
  join without knowing the plaintext name). Expose NetHash() helper.
- netmgr: add JoinByHash() — join via full 64-char hex hash alone,
  storing the short ID as display name. Enables joining yaw2 networks
  from a URL that only carries the hash.
- anchor: expose RunByHash() so netmgr can pass a pre-computed hash
  directly without a name→hash roundtrip.
- ipc/proto: add network_hash field to join_network — routes to
  JoinByHash when present and network_name is absent.

Web UI:
- Parse ?net=<64hex> (yaw2 URL param) and ?a=<anchor> in addition to
  existing ?n= / ?invite= params. Hash-only joins send network_hash.
- Sidebar shows yaw: contact card (yaw:<masterID>?n=<alias>) using the
  master identity — compatible with yaw2 contact card format. Click to
  copy to clipboard.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/src/pages/Onboarding.tsx

@@ -7,30 +7,42 @@ interface Props {
 
 // Parse URL search params for pre-filling the join form.
 // Supports:
-//   ?invite=waste:<b64>   waste: invite string (anchor + network name)
+//   ?invite=waste:<b64>   waste: invite string (anchor + network name + net hash)
 //   ?n=<name>             network name shorthand
 //   ?network=<name>       network name
+//   ?net=<64hex>          yaw2-style full network hash (joined without plaintext name)
 //   ?a=<url>              anchor URL hint (informational — daemon controls its anchor)
-function parseInviteParams(): { network: string; anchor: string; inviteString: string } {
+function parseInviteParams(): { network: string; netHash: string; anchor: string; inviteString: string } {
   const p = new URLSearchParams(window.location.search)
   const inviteString = p.get('invite') ?? ''
   let network = p.get('n') ?? p.get('network') ?? ''
+  let netHash = p.get('net') ?? ''
   let anchor = p.get('a') ?? p.get('anchor') ?? ''
 
   if (inviteString.startsWith('waste:')) {
     try {
+      // URL-safe base64 → standard base64
       const json = JSON.parse(atob(inviteString.slice(6).replace(/-/g, '+').replace(/_/g, '/')))
       network = network || json.network || ''
+      netHash = netHash || json.net || ''
       anchor = anchor || json.anchor || ''
     } catch { /* ignore bad invite */ }
   }
 
-  return { network, anchor, inviteString }
+  // URL path: /<16hex>/ — short network ID from anchor-served URL
+  const pathMatch = window.location.pathname.match(/\/([0-9a-f]{16})\/?$/i)
+  if (pathMatch && !netHash && !network) {
+    // Only the short ID — can't join by short ID alone (need full hash for HKDF).
+    // Store it as a hint; the user must supply the network name OR a full 64-char hash.
+  }
+
+  return { network, netHash, anchor, inviteString }
 }
 
 export function Onboarding({ status }: Props) {
   const { send, masterAlias, masterId, exportedBackup } = useWaste()
   const [network, setNetwork] = useState('')
+  const [netHash, setNetHash] = useState('')
   const [inviteString, setInviteString] = useState('')
   const [anchorHint, setAnchorHint] = useState('')
   const [exportPass, setExportPass] = useState('')
@@ -40,8 +52,9 @@ export function Onboarding({ status }: Props) {
   const [showBackup, setShowBackup] = useState(false)
 
   useEffect(() => {
-    const { network: n, anchor: a, inviteString: inv } = parseInviteParams()
+    const { network: n, netHash: nh, anchor: a, inviteString: inv } = parseInviteParams()
     if (n) setNetwork(n)
+    if (nh) setNetHash(nh)
     if (a) setAnchorHint(a)
     if (inv) setInviteString(inv)
   }, [])
@@ -49,8 +62,14 @@ export function Onboarding({ status }: Props) {
   function joinNetwork(e: React.FormEvent) {
     e.preventDefault()
     const name = network.trim()
-    if (!name) return
-    send({ type: 'join_network', network_name: name })
+    const hash = netHash.trim()
+    if (!name && !hash) return
+    if (hash.length === 64 && !name) {
+      // yaw2-style: join by full network hash without plaintext name
+      send({ type: 'join_network', network_hash: hash })
+    } else {
+      send({ type: 'join_network', network_name: name })
+    }
   }
 
   function exportIdentity(e: React.FormEvent) {
@@ -110,23 +129,31 @@ export function Onboarding({ status }: Props) {
         {anchorHint && (
           <p className="onboarding-hint muted">via {anchorHint}</p>
         )}
-        <input
-          value={network}
-          onChange={e => setNetwork(e.target.value)}
-          placeholder="network name"
-          autoComplete="off"
-          autoFocus
-        />
-        {inviteString && (
+        {netHash && !network ? (
           <input
-            value={inviteString}
-            readOnly
-            className="muted mono"
+            value={netHash}
+            onChange={e => setNetHash(e.target.value)}
+            placeholder="network hash (64 hex)"
+            autoComplete="off"
+            autoFocus
+            className="mono"
             style={{ fontSize: '0.72rem' }}
-            title="invite string"
+          />
+        ) : (
+          <input
+            value={network}
+            onChange={e => setNetwork(e.target.value)}
+            placeholder="network name"
+            autoComplete="off"
+            autoFocus
           />
         )}
-        <button type="submit" className="primary" disabled={!network.trim()}>
+        {inviteString && (
+          <p className="onboarding-hint muted mono" style={{ fontSize: '0.68rem', wordBreak: 'break-all' }}>
+            {inviteString.slice(0, 48)}…
+          </p>
+        )}
+        <button type="submit" className="primary" disabled={!network.trim() && netHash.length !== 64}>
           Join
         </button>
       </form>