fix(chat): restore a message's attached context on revert and fork

Review comments, quotes, terminal selections and annotations were consumed
at send and never put back, so reverting pulled the message into the
composer without the context it was sent with.

Claude-Session: https://claude.ai/code/session_01TwLFeTfBnWdvbg9XyezZQx

packages/ui/src/sync/session-actions.ts

@@ -16,6 +16,8 @@ import { registerSessionDirectory } from "./sync-refs"
 import { useGlobalSessionStatusStore } from "./global-session-status"
 import { recordSendFailure } from "./send-failure-log"
 import { isSyntheticPart } from "@/lib/messages/synthetic"
+import { draftFromContextPayload, readContextPart, type ContextCarrierPart } from "@/lib/messages/contextParts"
+import { useInlineCommentDraftStore, type InlineCommentDraftTarget } from "@/stores/useInlineCommentDraftStore"
 import { materializeSessionSnapshots } from "./materialization"
 import { stripMessageDiffSnapshots, stripSessionDiffSnapshots } from "./sanitize"
 import { sessionEvents } from "@/lib/sessionEvents"
@@ -598,6 +600,32 @@ function restoreFilePartsToInput(fileParts: Array<Record<string, unknown>>): voi
   }
 }
 
+/**
+ * Put a message's attached context (review comments, quotes, terminal
+ * selections, annotations) back on the composer chips.
+ *
+ * Context rides out as synthetic parts carrying structured metadata, so a
+ * reverted or forked message can be rebuilt into the drafts it came from.
+ * Without this the context is simply gone: the message is pulled back into the
+ * composer with its text and files, but the comments attached to it are not.
+ *
+ * The target's existing drafts are replaced, matching how text and file
+ * attachments are restored — the composer ends up as the message was sent.
+ */
+function restoreContextPartsToInput(
+  parts: readonly ContextCarrierPart[],
+  target: InlineCommentDraftTarget,
+): void {
+  const store = useInlineCommentDraftStore.getState()
+  store.clearDrafts(target)
+  for (const part of parts) {
+    const payload = readContextPart(part)
+    if (!payload) continue
+    const draft = draftFromContextPayload(payload)
+    if (draft) store.addDraft(target, draft)
+  }
+}
+
 /**
  * Server-confirmed directory that owns a session, from the session record
  * (`directory`, then `project.worktree`). Mirrors the authoritative source in
@@ -1985,6 +2013,7 @@ export async function revertToMessage(sessionId: string, messageId: string): Pro
   const targetMsg = messages.find((m) => m.id === messageId)
   let messageText = ""
   let submittedFileParts: Array<Record<string, unknown>> = []
+  let submittedContextParts: readonly ContextCarrierPart[] = []
   if (targetMsg && targetMsg.role === "user") {
     const parts = state.part[messageId] ?? []
     const textParts = parts.filter((p) => p.type === "text" && !isSyntheticPart(p))
@@ -1996,6 +2025,9 @@ export async function revertToMessage(sessionId: string, messageId: string): Pro
     // Exclude synthetic file parts (server-generated file content that should
     // not be restored to the composer).
     submittedFileParts = parts.filter((p) => p.type === "file" && !isSyntheticPart(p)) as Array<Record<string, unknown>>
+    // Attached context (review comments, quotes, terminal selections) rides in
+    // synthetic text parts and belongs back on the composer chips.
+    submittedContextParts = parts
   }
 
   // Optimistically set only the revert marker. Keep messages and parts in the
@@ -2023,6 +2055,10 @@ export async function revertToMessage(sessionId: string, messageId: string): Pro
   const prevInputAttachments = [...useInputStore.getState().attachedFiles]
   const prevInputText = useInputStore.getState().pendingInputText
   const prevInputMode = useInputStore.getState().pendingInputMode
+  const draftTarget: InlineCommentDraftTarget | null = directory
+    ? { directory, sessionKey: sessionId }
+    : null
+  const prevDrafts = draftTarget ? useInlineCommentDraftStore.getState().getDrafts(draftTarget) : []
 
   // Restore reverted message text and file attachments to input
   if (messageText) {
@@ -2036,6 +2072,7 @@ export async function revertToMessage(sessionId: string, messageId: string): Pro
   // Clear existing attachments first — previous revert's attachments
   // must not carry over, even when the current message has no files.
   restoreFilePartsToInput(submittedFileParts)
+  if (draftTarget) restoreContextPartsToInput(submittedContextParts, draftTarget)
 
   // Call SDK and merge authoritative result into store
   try {
@@ -2070,6 +2107,10 @@ export async function revertToMessage(sessionId: string, messageId: string): Pro
       pendingInputMode: prevInputMode,
       attachedFiles: prevInputAttachments,
     })
+    if (draftTarget) {
+      useInlineCommentDraftStore.getState().clearDrafts(draftTarget)
+      useInlineCommentDraftStore.getState().restoreDrafts(draftTarget, prevDrafts)
+    }
     throw err
   }
 }
@@ -2192,6 +2233,11 @@ export async function forkFromMessage(sessionId: string, messageId: string): Pro
   }
   // Clear existing attachments and restore file parts from the forked message.
   restoreFilePartsToInput(fileParts)
+  // The forked session is a fresh draft target, so the attached context of the
+  // forked message follows the text into its composer.
+  if (directory) {
+    restoreContextPartsToInput(parts, { directory, sessionKey: forkedSession.id })
+  }
 }
 
 export async function fetchMessagesForSession(sessionID: string, directory?: string | null): Promise<void> {