fix(httpapi): return project not found errors (#28856)

packages/opencode/test/server/httpapi-exercise/index.ts

@@ -177,6 +177,15 @@ const scenarios: Scenario[] = [
       },
       "status",
     ),
+  http.protected
+    .patch("/project/{projectID}", "project.update.missing")
+    .mutating()
+    .at((ctx) => ({
+      path: route("/project/{projectID}", { projectID: "project_httpapi_missing" }),
+      headers: ctx.headers(),
+      body: { name: "Missing Project" },
+    }))
+    .json(404, object, "status"),
   http.protected
     .post("/project/git/init", "project.initGit")
     .mutating()

packages/opencode/test/server/httpapi-instance.test.ts

@@ -9,6 +9,7 @@ import { ControlPaths } from "../../src/server/routes/instance/httpapi/groups/co
 import { InstancePaths } from "../../src/server/routes/instance/httpapi/groups/instance"
 import { SessionPaths } from "../../src/server/routes/instance/httpapi/groups/session"
 import { PermissionID } from "../../src/permission/schema"
+import { ProjectID } from "../../src/project/schema"
 import { QuestionID } from "../../src/question/schema"
 import { HttpApiApp } from "../../src/server/routes/instance/httpapi/server"
 import { HEADER as FenceHeader } from "../../src/server/shared/fence"
@@ -205,6 +206,30 @@ describe("instance HttpApi", () => {
     }),
   )
 
+  it.live("returns typed not found bodies for missing projects", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdirScoped({ git: true })
+      const projectID = ProjectID.make("project_missing")
+      const response = yield* Effect.promise(() =>
+        HttpApiApp.webHandler().handler(
+          new Request(`http://localhost/project/${projectID}`, {
+            method: "PATCH",
+            headers: { "x-opencode-directory": dir, "content-type": "application/json" },
+            body: JSON.stringify({ name: "Missing" }),
+          }),
+          handlerContext,
+        ),
+      )
+
+      expect(response.status).toBe(404)
+      expect(yield* Effect.promise(() => response.json())).toEqual({
+        _tag: "ProjectNotFoundError",
+        projectID,
+        message: `Project not found: ${projectID}`,
+      })
+    }),
+  )
+
   it.live("serves path and VCS read endpoints", () =>
     Effect.gen(function* () {
       const dir = yield* tmpdirScoped({ git: true })

packages/opencode/test/server/httpapi-public-openapi.test.ts

@@ -208,4 +208,12 @@ describe("PublicApi OpenAPI v2 errors", () => {
       "PtyForbiddenError",
     )
   })
+
+  test("documents project not-found errors", () => {
+    const spec = OpenApi.fromApi(PublicApi) as OpenApiSpec
+
+    expect(componentName(responseRef(spec.paths["/project/{projectID}"]?.patch?.responses?.["404"]) ?? "")).toBe(
+      "ProjectNotFoundError",
+    )
+  })
 })