feat: anthropic-style mesh + invite redesign (wave 1 checkpoint)

Ships the user-visible friction fixes and the foundation for the v2
invite protocol. API wiring + CLI client + email UI ship in wave 2.

Meshes — shipped
- Drop global UNIQUE on mesh.slug; mesh.id is canonical everywhere
- Server derives slug from name; create form has no slug field
- Two users can freely name their mesh "platform"; no collision errors
- Migration 0017

Invites v1 — shipped (URL shortener, backward compatible)
- New invite.code column (base62, 8 chars, nullable unique index)
- createMyInvite mints both token + short code; returns shortUrl
- GET /api/public/invite-code/:code resolves short code to token
- New route /i/[code] server-redirects to /join/[token]
- Invite generator UI shows short URL; QR encodes short URL
- Advanced fields (role/maxUses/expiresInDays) collapsed under disclosure
- Migration 0018

Invites v2 — foundation (broker + DB only; API+CLI+Web wiring in wave 2)
- Broker: canonicalInviteV2, verifyInviteV2, sealRootKeyToRecipient
- Broker: POST /invites/:code/claim endpoint (atomic single-use accounting)
- Broker tests: invite-v2.test.ts (signature, expiry, revocation, exhaustion)
- DB: mesh.invite gains version/capabilityV2/claimedByPubkey columns
- DB: new mesh.pending_invite table for email invites
- Migration 0019
- Contract locked in docs/protocol.md §v2 + SPEC.md §14b

Consent landing — shipped
- /join/[token] redesigned: explicit role, inviter, mesh stats, consent
- New server components: invite-card, role-badge, inviter-line, consent-summary
- "Join [mesh] as [Role]" primary action (not just "Join")

Error surfacing — shipped
- handle() now parses {error} responses from hono route catch blocks
- onError fallback includes timestamp so handle() can match apiErrorSchema
- Real error messages reach the UI instead of "Something went wrong"

Docs
- SPEC.md §14b: v2 invite protocol
- docs/protocol.md: v2 claim wire format
- docs/roadmap.md: status
- .artifacts/specs/2026-04-10-anthropic-vision-meshes-invites.md

Deferred to wave 2/3
- API claim route wiring (packages/api)
- createMyInvite v2 capability generation
- Email invite mutation + Postmark delivery
- CLI v2 join flow (x25519 keypair + unseal)
- Web invite-generator email field + v2 display

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/api/src/utils/index.ts

@@ -22,6 +22,11 @@ const apiErrorSchema = z.object({
   path: z.string(),
 });
 
+/** Matches the `{ error: "..." }` shape returned by Hono route catch blocks. */
+const routeErrorSchema = z.object({
+  error: z.string(),
+});
+
 export const isAPIError = (e: unknown): e is z.infer<typeof apiErrorSchema> => {
   return apiErrorSchema.safeParse(e).success;
 };
@@ -70,10 +75,13 @@ export const handle = <
 
     if (!response.ok) {
       if (throwOnError) {
+        const parsed = routeErrorSchema.safeParse(data);
         throw new Error(
           isAPIError(data)
             ? data.message
-            : "Something went wrong. Please try again later.",
+            : parsed.success
+              ? parsed.data.error
+              : "Something went wrong. Please try again later.",
         );
       }
       return null as HandleReturn<TResponse, E, S>;

packages/api/src/utils/on-error.ts

@@ -69,6 +69,7 @@ export const onError = async (
       code: "common:error.general",
       message: t("common:error.general"),
       status,
+      timestamp,
       path,
     }),
     details,