feat(feedback): add the Web surface for message feedback

Consume the durable message-feedback sidecar from #2217 in the browser:
per-message Like/Dislike with an optional note, contributed through a
declared assistant-actions slot.

- carry MessageId on finalized AssistantMessageNode so a target is nameable
- declare conversation.chat.assistant-actions and render it in the
  IconActions row between copy and branch
- hold one FeedbackController per Session with per-item ifVersion CAS,
  reconciling a version-conflict from the reply's authoritative item
- mount messageFeedbackRemote alongside goalsRemote

packages/api/remotes/package.json

@@ -56,6 +56,7 @@
     "@deepseek-ai/dsh-agent": "workspace:^",
     "@deepseek-ai/dsh-goal": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@deepseek-ai/dsh-message-feedback": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-persistence": "workspace:^",
     "@deepseek-ai/dsh-typert-registry": "workspace:^",
@@ -65,6 +66,7 @@
     "@deepseek-ai/dsh-agent": "workspace:^",
     "@deepseek-ai/dsh-goal": "workspace:^",
     "@deepseek-ai/dsh-invariants": "workspace:^",
+    "@deepseek-ai/dsh-message-feedback": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
     "@deepseek-ai/dsh-session-persistence": "workspace:^",
     "@deepseek-ai/dsh-typert-registry": "workspace:^",

packages/api/remotes/src/client/index.ts

@@ -2,10 +2,12 @@
 
 import type { Context } from '@deepseek-ai/cordis'
 import goalsRemote from '@deepseek-ai/dsh-goal/remote'
+import messageFeedbackRemote from '@deepseek-ai/dsh-message-feedback/remote'
 import type { TypeRTClientRemote } from '@deepseek-ai/dsh-type-meta'
 
 export type { TypeRTClientRemote as ClientRemote } from '@deepseek-ai/dsh-type-meta'
 export type {} from '@deepseek-ai/dsh-goal/remote'
+export type {} from '@deepseek-ai/dsh-message-feedback/remote'
 
 declare module '@deepseek-ai/cordis' {
   interface Context {
@@ -23,5 +25,11 @@ export const inject = ['remote']
  * @returns disposer after every selected Remote namespace is ready.
  */
 export async function apply(ctx: Context): Promise<() => Promise<void>> {
-  return await ctx.remote.$mount(goalsRemote)
+  const mounted = [
+    await ctx.remote.$mount(goalsRemote),
+    await ctx.remote.$mount(messageFeedbackRemote),
+  ]
+  return async () => {
+    for (const dispose of mounted.reverse()) await dispose()
+  }
 }

packages/api/remotes/tsconfig.client.json

@@ -15,6 +15,9 @@
     {
       "path": "../../goal/goal"
     },
+    {
+      "path": "../../feedback/message-feedback"
+    },
     {
       "path": "../../typert/type-meta"
     }