feat(message-queue): per-conversation queue + steering injection

A per-conversation message queue (new message-queue extension) holds user
messages enqueued while a turn generates; delivered mid-turn as steering at the
tool-result boundary (or carried to a new turn if no tool call fires).

- kernel: RunTurnInput.drainSteering callback (generic; kernel stays pure)
- wire 0.7.0->0.8.0: QueuedMessage, QueuePayload, TurnSteeringEvent (additive)
- transport-contract 0.11.0->0.12.0: POST /conversations/:id/queue + chat.queue WS op
- message-queue ext: queue state + per-conversation custom surface (rendererId message-queue)
- session-orchestrator: enqueue facade + drainSteering wiring + post-seal carry
- transport-http/ws: queue endpoint + chat.queue op (fixes WsClientMessage exhaustive switch)
- host-bin: register message-queue

1043 vitest + 199 transport bun pass; tsc/biome clean; boot smoke clean.
FE courier: frontend-message-queue-handoff.md.

1 files changed, 25 insertions, 3 deletions

diff --git a/bun.lock b/bun.lock
index f98aa26..5716c6a 100644
--- a/bun.lock
+++ b/bun.lock
@@ -97,6 +97,16 @@
         "@dispatch/kernel": "workspace:*",
       },
     },
+    "packages/message-queue": {
+      "name": "@dispatch/message-queue",
+      "version": "0.0.0",
+      "dependencies": {
+        "@dispatch/kernel": "workspace:*",
+        "@dispatch/surface-registry": "workspace:*",
+        "@dispatch/ui-contract": "workspace:*",
+        "@dispatch/wire": "workspace:*",
+      },
+    },
     "packages/observability-collector": {
       "name": "@dispatch/observability-collector",
       "version": "0.0.0",
@@ -120,6 +130,7 @@
         "@dispatch/conversation-store": "workspace:*",
         "@dispatch/credential-store": "workspace:*",
         "@dispatch/kernel": "workspace:*",
+        "@dispatch/message-queue": "workspace:*",
       },
     },
     "packages/skills": {
@@ -182,6 +193,13 @@
         "@dispatch/kernel": "workspace:*",
       },
     },
+    "packages/tool-web-search": {
+      "name": "@dispatch/tool-web-search",
+      "version": "0.0.0",
+      "dependencies": {
+        "@dispatch/kernel": "workspace:*",
+      },
+    },
     "packages/tool-write-file": {
       "name": "@dispatch/tool-write-file",
       "version": "0.0.0",
@@ -202,7 +220,7 @@
     },
     "packages/transport-contract": {
       "name": "@dispatch/transport-contract",
-      "version": "0.5.0",
+      "version": "0.12.0",
       "dependencies": {
         "@dispatch/ui-contract": "workspace:*",
         "@dispatch/wire": "workspace:*",
@@ -235,11 +253,11 @@
     },
     "packages/ui-contract": {
       "name": "@dispatch/ui-contract",
-      "version": "0.1.0",
+      "version": "0.2.0",
     },
     "packages/wire": {
       "name": "@dispatch/wire",
-      "version": "0.4.0",
+      "version": "0.8.0",
     },
   },
   "packages": {
@@ -279,6 +297,8 @@
 
     "@dispatch/lsp": ["@dispatch/lsp@workspace:packages/lsp"],
 
+    "@dispatch/message-queue": ["@dispatch/message-queue@workspace:packages/message-queue"],
+
     "@dispatch/observability-collector": ["@dispatch/observability-collector@workspace:packages/observability-collector"],
 
     "@dispatch/provider-openai-compat": ["@dispatch/provider-openai-compat@workspace:packages/provider-openai-compat"],
@@ -301,6 +321,8 @@
 
     "@dispatch/tool-shell": ["@dispatch/tool-shell@workspace:packages/tool-shell"],
 
+    "@dispatch/tool-web-search": ["@dispatch/tool-web-search@workspace:packages/tool-web-search"],
+
     "@dispatch/tool-write-file": ["@dispatch/tool-write-file@workspace:packages/tool-write-file"],
 
     "@dispatch/trace-replay": ["@dispatch/trace-replay@workspace:packages/trace-replay"],