feat: v2 Phase 1 — foundation, proto schemas, RPC framework, SDK skeleton

New workspace structure with 9 crates. Adds:

- proto/qpq/v1/*.proto: 11 protobuf schemas covering all 33 RPC methods
- quicproquo-proto: dual codegen (capnp legacy + prost v2)
- quicproquo-rpc: QUIC RPC framework (framing, server, client, middleware)
- quicproquo-sdk: client SDK (QpqClient, events, conversation store)
- quicproquo-server/domain/: protocol-agnostic domain types and services
- justfile: build commands

Wire format: [method_id:u16][req_id:u32][len:u32][protobuf] per QUIC stream.
All 151 existing tests pass. Backward compatible with v1 capnp code.

proto/qpq/v1/auth.proto

@@ -0,0 +1,43 @@
+syntax = "proto3";
+package qpq.v1;
+
+// OPAQUE registration + login (4 methods).
+// Method IDs: 100-103.
+
+message OpaqueRegisterStartRequest {
+  string username = 1;
+  bytes request = 2;
+}
+
+message OpaqueRegisterStartResponse {
+  bytes response = 1;
+}
+
+message OpaqueRegisterFinishRequest {
+  string username = 1;
+  bytes upload = 2;
+  bytes identity_key = 3;
+}
+
+message OpaqueRegisterFinishResponse {
+  bool success = 1;
+}
+
+message OpaqueLoginStartRequest {
+  string username = 1;
+  bytes request = 2;
+}
+
+message OpaqueLoginStartResponse {
+  bytes response = 1;
+}
+
+message OpaqueLoginFinishRequest {
+  string username = 1;
+  bytes finalization = 2;
+  bytes identity_key = 3;
+}
+
+message OpaqueLoginFinishResponse {
+  bytes session_token = 1;
+}

proto/qpq/v1/blob.proto

@@ -0,0 +1,29 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Blob upload/download (2 methods).
+// Method IDs: 600-601.
+
+message UploadBlobRequest {
+  bytes blob_hash = 1;
+  bytes chunk = 2;
+  uint64 offset = 3;
+  uint64 total_size = 4;
+  string mime_type = 5;
+}
+
+message UploadBlobResponse {
+  bytes blob_id = 1;
+}
+
+message DownloadBlobRequest {
+  bytes blob_id = 1;
+  uint64 offset = 2;
+  uint32 length = 3;
+}
+
+message DownloadBlobResponse {
+  bytes chunk = 1;
+  uint64 total_size = 2;
+  string mime_type = 3;
+}

proto/qpq/v1/channel.proto

@@ -0,0 +1,14 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Channel create (1 method).
+// Method ID: 400.
+
+message CreateChannelRequest {
+  bytes peer_key = 1;
+}
+
+message CreateChannelResponse {
+  bytes channel_id = 1;
+  bool was_new = 2;
+}

proto/qpq/v1/common.proto

@@ -0,0 +1,19 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Common types shared across services.
+
+// Auth context included in authenticated RPC requests.
+// In v2, this is carried as QUIC connection-level state (session token),
+// not per-message. Included here for federation and internal use.
+message Auth {
+  bytes access_token = 1;
+  bytes device_id = 2;
+}
+
+// Account deletion.
+message DeleteAccountRequest {}
+
+message DeleteAccountResponse {
+  bool success = 1;
+}

proto/qpq/v1/delivery.proto

@@ -0,0 +1,72 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Delivery service: enqueue, fetch, peek, ack, batch (6 methods).
+// Method IDs: 200-205.
+
+message Envelope {
+  uint64 seq = 1;
+  bytes data = 2;
+}
+
+message EnqueueRequest {
+  bytes recipient_key = 1;
+  bytes payload = 2;
+  bytes channel_id = 3;
+  uint32 ttl_secs = 4;
+}
+
+message EnqueueResponse {
+  uint64 seq = 1;
+  bytes delivery_proof = 2;
+}
+
+message FetchRequest {
+  bytes recipient_key = 1;
+  bytes channel_id = 2;
+  uint32 limit = 3;
+}
+
+message FetchResponse {
+  repeated Envelope payloads = 1;
+}
+
+message FetchWaitRequest {
+  bytes recipient_key = 1;
+  bytes channel_id = 2;
+  uint64 timeout_ms = 3;
+  uint32 limit = 4;
+}
+
+message FetchWaitResponse {
+  repeated Envelope payloads = 1;
+}
+
+message PeekRequest {
+  bytes recipient_key = 1;
+  bytes channel_id = 2;
+  uint32 limit = 3;
+}
+
+message PeekResponse {
+  repeated Envelope payloads = 1;
+}
+
+message AckRequest {
+  bytes recipient_key = 1;
+  bytes channel_id = 2;
+  uint64 seq_up_to = 3;
+}
+
+message AckResponse {}
+
+message BatchEnqueueRequest {
+  repeated bytes recipient_keys = 1;
+  bytes payload = 2;
+  bytes channel_id = 3;
+  uint32 ttl_secs = 4;
+}
+
+message BatchEnqueueResponse {
+  repeated uint64 seqs = 1;
+}

proto/qpq/v1/device.proto

@@ -0,0 +1,34 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Device register/list/revoke (3 methods).
+// Method IDs: 700-702.
+
+message RegisterDeviceRequest {
+  bytes device_id = 1;
+  string device_name = 2;
+}
+
+message RegisterDeviceResponse {
+  bool success = 1;
+}
+
+message ListDevicesRequest {}
+
+message ListDevicesResponse {
+  repeated Device devices = 1;
+}
+
+message Device {
+  bytes device_id = 1;
+  string device_name = 2;
+  uint64 registered_at = 3;
+}
+
+message RevokeDeviceRequest {
+  bytes device_id = 1;
+}
+
+message RevokeDeviceResponse {
+  bool success = 1;
+}

proto/qpq/v1/federation.proto

@@ -0,0 +1,65 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Federation relay + proxy (6 methods).
+// Method IDs: 900-905.
+
+message FederationAuth {
+  string origin = 1;
+}
+
+message RelayEnqueueRequest {
+  bytes recipient_key = 1;
+  bytes payload = 2;
+  bytes channel_id = 3;
+  FederationAuth auth = 4;
+}
+
+message RelayEnqueueResponse {
+  uint64 seq = 1;
+}
+
+message RelayBatchEnqueueRequest {
+  repeated bytes recipient_keys = 1;
+  bytes payload = 2;
+  bytes channel_id = 3;
+  FederationAuth auth = 4;
+}
+
+message RelayBatchEnqueueResponse {
+  repeated uint64 seqs = 1;
+}
+
+message ProxyFetchKeyPackageRequest {
+  bytes identity_key = 1;
+  FederationAuth auth = 2;
+}
+
+message ProxyFetchKeyPackageResponse {
+  bytes package = 1;
+}
+
+message ProxyFetchHybridKeyRequest {
+  bytes identity_key = 1;
+  FederationAuth auth = 2;
+}
+
+message ProxyFetchHybridKeyResponse {
+  bytes hybrid_public_key = 1;
+}
+
+message ProxyResolveUserRequest {
+  string username = 1;
+  FederationAuth auth = 2;
+}
+
+message ProxyResolveUserResponse {
+  bytes identity_key = 1;
+}
+
+message FederationHealthRequest {}
+
+message FederationHealthResponse {
+  string status = 1;
+  string server_domain = 2;
+}

proto/qpq/v1/keys.proto

@@ -0,0 +1,45 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Key package + hybrid key CRUD (5 methods).
+// Method IDs: 300-304.
+
+message UploadKeyPackageRequest {
+  bytes identity_key = 1;
+  bytes package = 2;
+}
+
+message UploadKeyPackageResponse {
+  bytes fingerprint = 1;
+}
+
+message FetchKeyPackageRequest {
+  bytes identity_key = 1;
+}
+
+message FetchKeyPackageResponse {
+  bytes package = 1;
+}
+
+message UploadHybridKeyRequest {
+  bytes identity_key = 1;
+  bytes hybrid_public_key = 2;
+}
+
+message UploadHybridKeyResponse {}
+
+message FetchHybridKeyRequest {
+  bytes identity_key = 1;
+}
+
+message FetchHybridKeyResponse {
+  bytes hybrid_public_key = 1;
+}
+
+message FetchHybridKeysRequest {
+  repeated bytes identity_keys = 1;
+}
+
+message FetchHybridKeysResponse {
+  repeated bytes keys = 1;
+}

proto/qpq/v1/p2p.proto

@@ -0,0 +1,26 @@
+syntax = "proto3";
+package qpq.v1;
+
+// P2P endpoint publish/resolve + health (3 methods).
+// Method IDs: 800-802.
+
+message PublishEndpointRequest {
+  bytes identity_key = 1;
+  bytes node_addr = 2;
+}
+
+message PublishEndpointResponse {}
+
+message ResolveEndpointRequest {
+  bytes identity_key = 1;
+}
+
+message ResolveEndpointResponse {
+  bytes node_addr = 1;
+}
+
+message HealthRequest {}
+
+message HealthResponse {
+  string status = 1;
+}

proto/qpq/v1/push.proto

@@ -0,0 +1,49 @@
+syntax = "proto3";
+package qpq.v1;
+
+// Server-push event types (sent on QUIC uni-streams).
+// Event type IDs: 1000+.
+
+// Wrapper for a push event.
+message PushEvent {
+  oneof event {
+    NewMessage new_message = 1;
+    TypingIndicator typing = 2;
+    PresenceUpdate presence = 3;
+    GroupMembershipChange membership = 4;
+  }
+}
+
+message NewMessage {
+  bytes channel_id = 1;
+  bytes sender_key = 2;
+  uint64 seq = 3;
+  bytes payload = 4;
+  uint64 timestamp_ms = 5;
+}
+
+message TypingIndicator {
+  bytes channel_id = 1;
+  bytes sender_key = 2;
+  bool is_typing = 3;
+}
+
+message PresenceUpdate {
+  bytes identity_key = 1;
+  bool online = 2;
+  uint64 last_seen_ms = 3;
+}
+
+message GroupMembershipChange {
+  bytes channel_id = 1;
+  bytes actor_key = 2;
+  bytes target_key = 3;
+  MembershipAction action = 4;
+}
+
+enum MembershipAction {
+  MEMBERSHIP_ACTION_UNSPECIFIED = 0;
+  MEMBERSHIP_ACTION_ADDED = 1;
+  MEMBERSHIP_ACTION_REMOVED = 2;
+  MEMBERSHIP_ACTION_LEFT = 3;
+}

proto/qpq/v1/user.proto

@@ -0,0 +1,22 @@
+syntax = "proto3";
+package qpq.v1;
+
+// User resolve + identity (2 methods).
+// Method IDs: 500-501.
+
+message ResolveUserRequest {
+  string username = 1;
+}
+
+message ResolveUserResponse {
+  bytes identity_key = 1;
+  bytes inclusion_proof = 2;
+}
+
+message ResolveIdentityRequest {
+  bytes identity_key = 1;
+}
+
+message ResolveIdentityResponse {
+  string username = 1;
+}