fix(acp): preserve resource text source (#33524)

packages/opencode/test/acp/content.test.ts

@@ -99,17 +99,29 @@ describe("acp content conversion", () => {
     ])
   })
 
-  test("resource with text becomes a text part", () => {
+  test("resource with text becomes a sourced text part", () => {
     expect(
       contentBlockToParts({
         type: "resource",
         resource: {
-          uri: "file:///tmp/context.txt",
+          uri: "file:///tmp/context.txt#L12-L14",
           mimeType: "text/plain",
           text: "context",
         },
       }),
-    ).toEqual([{ type: "text", text: "context" }])
+    ).toEqual([{ type: "text", text: "[/tmp/context.txt:12]\ncontext" }])
+  })
+
+  test("resource with text uses URI fallback for non-file resources", () => {
+    expect(
+      contentBlockToParts({
+        type: "resource",
+        resource: {
+          uri: "mcp://server/context",
+          text: "context",
+        },
+      }),
+    ).toEqual([{ type: "text", text: "[mcp://server/context]\ncontext" }])
   })
 
   test("resource with blob and mimeType becomes a data URL file part", () => {