feat(08-02): add ensureGeneralistAgents startup migration for existing workspaces

- Import agentService and agents table into server/src/index.ts
- ensureGeneralistAgents() queries all companies, skips any that already have
  a general-role agent (idempotent), creates Generalist via agentService.create()
- metadata includes pendingSkillGroups: [Creative] and backfilled: true flag
- Called with fire-and-forget void pattern after ensureLocalTrustedBoardPrincipal
- Existing workspaces get Generalist on next server upgrade without user action

server/src/index.ts

@@ -19,6 +19,7 @@ import {
   formatDatabaseBackupResult,
   runDatabaseBackup,
   authUsers,
+  agents,
   companies,
   companyMemberships,
   instanceUserRoles,
@@ -28,7 +29,7 @@ import { createApp } from "./app.js";
 import { loadConfig } from "./config.js";
 import { logger } from "./middleware/logger.js";
 import { setupLiveEventsWebSocketServer } from "./realtime/live-events-ws.js";
-import { heartbeatService, reconcilePersistedRuntimeServicesOnStartup, routineService } from "./services/index.js";
+import { agentService, heartbeatService, reconcilePersistedRuntimeServicesOnStartup, routineService } from "./services/index.js";
 import { createStorageServiceFromConfig } from "./storage/index.js";
 import { printStartupBanner } from "./startup-banner.js";
 import { getBoardClaimWarningUrl, initializeBoardClaimChallenge } from "./board-claim.js";
@@ -243,6 +244,32 @@ export async function startServer(): Promise<StartedServer> {
     }
   }
   
+  // [nexus] Backfill Generalist agent for existing workspaces that pre-date Phase 8
+  async function ensureGeneralistAgents(db: any): Promise<{ backfilled: number }> {
+    const companyRows = await db.select({ id: companies.id }).from(companies);
+    let backfilled = 0;
+    for (const company of companyRows) {
+      const existing = await db
+        .select({ id: agents.id })
+        .from(agents)
+        .where(and(eq(agents.companyId, company.id), eq(agents.role, "general")))
+        .then((rows: Array<{ id: string }>) => rows[0] ?? null);
+      if (existing) continue;
+      const agentSvc = agentService(db);
+      await agentSvc.create(company.id, {
+        name: "Generalist",
+        role: "general",
+        adapterType: "claude_local",
+        adapterConfig: {},
+        runtimeConfig: {},
+        metadata: { pendingSkillGroups: ["Creative"], backfilled: true },
+      });
+      logger.info({ companyId: company.id }, "backfilled Generalist agent for existing workspace");
+      backfilled++;
+    }
+    return { backfilled };
+  }
+
   let db;
   let embeddedPostgres: EmbeddedPostgresInstance | null = null;
   let embeddedPostgresStartedByThisProcess = false;
@@ -459,6 +486,18 @@ export async function startServer(): Promise<StartedServer> {
   if (config.deploymentMode === "local_trusted") {
     await ensureLocalTrustedBoardPrincipal(db as any);
   }
+
+  // [nexus] Backfill Generalist agents for any workspace that pre-dates Phase 8
+  void ensureGeneralistAgents(db as any)
+    .then((result) => {
+      if (result.backfilled > 0) {
+        logger.info({ backfilled: result.backfilled }, "backfilled Generalist agents for existing workspaces");
+      }
+    })
+    .catch((err) => {
+      logger.error({ err }, "failed to backfill Generalist agents");
+    });
+
   if (config.deploymentMode === "authenticated") {
     const {
       createBetterAuthHandler,