feat: wire multi-repo paths through session and agent

Pass additional repository paths from multi-repo workspaces through to the
agent session:

- ConnectParams: add additionalRepoPaths field
- SessionService.createNewLocalSession: forward additionalDirectories to
  agent.start mutation
- TaskCreationSaga: resolve additional workspace paths from workspace.getInfo
  and pass them as additionalRepoPaths
- workspaceEnv: add buildMultiRepoWorkspaceEnv with indexed per-repo env vars
  (POSTHOG_CODE_REPO_0_NAME, POSTHOG_CODE_REPO_0_PATH, etc.)

Generated-By: PostHog Code
Task-Id: 230ec8e6-6781-43b4-ae30-ea24faa410dc

Author: richardsolomou

apps/code/src/main/services/workspace/workspaceEnv.ts

@@ -8,6 +8,12 @@ export interface WorkspaceEnvContext {
   worktreePath: string | null;
   worktreeName: string | null;
   mode: WorkspaceMode;
+  label?: string | null;
+}
+
+export interface MultiRepoEnvContext {
+  taskId: string;
+  workspaces: WorkspaceEnvContext[];
 }
 
 const PORT_BASE = 50000;
@@ -71,3 +77,43 @@ export async function buildWorkspaceEnv(
     POSTHOG_CODE_WORKSPACE_PORTS_END: String(portAllocation.end),
   };
 }
+
+/**
+ * Build env vars for multi-repo tasks. Includes indexed per-repo vars
+ * (POSTHOG_CODE_REPO_0_*, POSTHOG_CODE_REPO_1_*, etc.) alongside the
+ * legacy single-repo vars from the first workspace.
+ */
+export async function buildMultiRepoWorkspaceEnv(
+  context: MultiRepoEnvContext,
+): Promise<Record<string, string>> {
+  const nonCloudWorkspaces = context.workspaces.filter(
+    (ws) => ws.mode !== "cloud",
+  );
+  if (nonCloudWorkspaces.length === 0) return {};
+
+  // Legacy vars from first workspace
+  const legacyEnv = await buildWorkspaceEnv(nonCloudWorkspaces[0]);
+
+  // Indexed per-repo vars
+  const repoEnv: Record<string, string> = {
+    POSTHOG_CODE_REPO_COUNT: String(nonCloudWorkspaces.length),
+  };
+
+  for (let i = 0; i < nonCloudWorkspaces.length; i++) {
+    const ws = nonCloudWorkspaces[i];
+    const prefix = `POSTHOG_CODE_REPO_${i}`;
+    const wsPath = ws.worktreePath ?? ws.folderPath;
+    const wsName = ws.label ?? ws.worktreeName ?? path.basename(ws.folderPath);
+
+    repoEnv[`${prefix}_NAME`] = wsName;
+    repoEnv[`${prefix}_PATH`] = wsPath;
+
+    try {
+      repoEnv[`${prefix}_BRANCH`] = (await getCurrentBranch(wsPath)) ?? "";
+    } catch {
+      repoEnv[`${prefix}_BRANCH`] = "";
+    }
+  }
+
+  return { ...legacyEnv, ...repoEnv };
+}

apps/code/src/renderer/features/sessions/service/service.ts

@@ -70,6 +70,8 @@ interface AuthCredentials {
 export interface ConnectParams {
   task: Task;
   repoPath: string;
+  /** Additional repo paths for multi-repo tasks (passed as additionalDirectories to agent). */
+  additionalRepoPaths?: string[];
   initialPrompt?: ContentBlock[];
   executionMode?: ExecutionMode;
   adapter?: "claude" | "codex";
@@ -178,6 +180,7 @@ export class SessionService {
     const {
       task,
       repoPath,
+      additionalRepoPaths,
       initialPrompt,
       executionMode,
       adapter,
@@ -282,6 +285,7 @@ export class SessionService {
           adapter,
           model,
           reasoningLevel,
+          additionalRepoPaths,
         );
       }
     } catch (error) {
@@ -537,6 +541,7 @@ export class SessionService {
     adapter?: "claude" | "codex",
     model?: string,
     reasoningLevel?: string,
+    additionalRepoPaths?: string[],
   ): Promise<void> {
     const { client } = auth;
     if (!client) {
@@ -564,6 +569,7 @@ export class SessionService {
         ? (reasoningLevel as EffortLevel)
         : undefined,
       model: preferredModel,
+      additionalDirectories: additionalRepoPaths,
     });
 
     const session = this.createBaseSession(taskRun.id, taskId, taskTitle);

apps/code/src/renderer/sagas/task/task-creation.ts

@@ -301,15 +301,28 @@ export class TaskCreationSaga extends Saga<
             )
           : undefined;
 
+      // Resolve additional repo paths from multi-repo workspaces
+      let additionalRepoPaths: string[] | undefined;
+      if (!input.taskId) {
+        // New task: resolve from workspace creation results
+        const allWorkspaces = await trpcClient.workspace.getInfo.query({
+          taskId: task.id,
+        });
+        if (allWorkspaces.length > 1) {
+          additionalRepoPaths = allWorkspaces
+            .slice(1)
+            .map((ws) => ws.worktree?.worktreePath)
+            .filter((p): p is string => !!p);
+        }
+      }
+
       await this.step({
         name: "agent_session",
         execute: async () => {
-          // Fire-and-forget for both open and create paths.
-          // The UI handles "connecting" state with a spinner (TaskLogsPanel),
-          // so we don't need to block the saga on the full reconnect chain.
           const connectParams: ConnectParams = {
             task,
             repoPath: agentCwd ?? "",
+            additionalRepoPaths,
           };
           if (initialPrompt) connectParams.initialPrompt = initialPrompt;
           if (input.executionMode)