feat: add project workspaces (DB, API, service, and UI)

New project_workspaces table with primary workspace designation.
Full CRUD routes, service with auto-primary promotion on delete,
workspace management UI in project properties panel, and workspace
data included in project/issue ancestor responses.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/db/src/schema/project_workspaces.ts

@@ -0,0 +1,32 @@
+import {
+  boolean,
+  index,
+  jsonb,
+  pgTable,
+  text,
+  timestamp,
+  uuid,
+} from "drizzle-orm/pg-core";
+import { companies } from "./companies.js";
+import { projects } from "./projects.js";
+
+export const projectWorkspaces = pgTable(
+  "project_workspaces",
+  {
+    id: uuid("id").primaryKey().defaultRandom(),
+    companyId: uuid("company_id").notNull().references(() => companies.id),
+    projectId: uuid("project_id").notNull().references(() => projects.id, { onDelete: "cascade" }),
+    name: text("name").notNull(),
+    cwd: text("cwd").notNull(),
+    repoUrl: text("repo_url"),
+    repoRef: text("repo_ref"),
+    metadata: jsonb("metadata").$type<Record<string, unknown>>(),
+    isPrimary: boolean("is_primary").notNull().default(false),
+    createdAt: timestamp("created_at", { withTimezone: true }).notNull().defaultNow(),
+    updatedAt: timestamp("updated_at", { withTimezone: true }).notNull().defaultNow(),
+  },
+  (table) => ({
+    companyProjectIdx: index("project_workspaces_company_project_idx").on(table.companyId, table.projectId),
+    projectPrimaryIdx: index("project_workspaces_project_primary_idx").on(table.projectId, table.isPrimary),
+  }),
+);