feat(discord-gateway): use Discord CDN for image analysis, uploader archive-only

- mediaDownloader: flip URL candidate order so discord_url is tried
  before uploaded_url (uploaded_url is archive-only fallback)
- ai-analysis-worker: remove upload-pending race guard that blocked
  analysis until Tele upload completed; analysis now runs immediately
  on the Discord CDN URL
- batchProcessor: remove upload-pending defer/poll-backoff logic
- individualFallbackProcessor: remove upload_pending requeue loop
- batchOutcomeClassifier/fallbackResultClassifier: drop upload_pending
  classification (no longer needed)
- tests: update batchOutcomeClassifier + fallbackResultClassifier tests
  to reflect removed upload_pending signal

services/discord-gateway/tests/batchOutcomeClassifier.test.ts

@@ -1,53 +1,35 @@
 // ═══════════════════════════════════════════════════════════════════════════
-// partitionBatchOutcome — upload-pending defer vs fanout (2026-08-25)
-// ═══════════════════════════════════════════════════════════════════════════
-// Bug history: the batch worker's race guard returned {ok:true, rows:[]} while
-// attachments were still uploading; every target was classified "incomplete",
-// fanned out to the individual queue, requeued there, rescheduled at 250ms —
-// a hot ~300ms loop for the whole upload duration (~10 cycles in 3s in prod).
+// partitionBatchOutcome — per-message disposition (2026-08-28)
+//
+// Upload-pending race guard removed: analysis no longer depends on the Tele
+// uploader. The worker always runs analysis on the Discord CDN URL directly,
+// so there are no upload-pending targets to defer.
 import { describe, expect, it } from "vitest";
-import {
-  computeUploadPollDelayMs,
-  partitionBatchOutcome,
-} from "../src/modules/ai-moderation/batchOutcomeClassifier.js";
+import { partitionBatchOutcome } from "../src/modules/ai-moderation/batchOutcomeClassifier.js";
 
 const msgs = (...ids: string[]) => ids.map((id) => ({ id }));
 
 describe("partitionBatchOutcome", () => {
-  it("marks ALL targets upload_pending when the full-batch guard fires", () => {
+  it("classifies a fully-analyzed batch as completed", () => {
     const out = partitionBatchOutcome(msgs("a", "b"), {
-      ok: true,
-      rows: [],
-      uploadPendingIds: ["a", "b"],
-    });
-    expect(out.get("a")).toBe("upload_pending");
-    expect(out.get("b")).toBe("upload_pending");
-  });
-
-  it("never classifies an explicit upload_pending id as incomplete", () => {
-    // The regression this file exists for: uploadPendingIds must win over the
-    // missing-row heuristic.
-    const out = partitionBatchOutcome(msgs("a"), {
-      ok: true,
-      rows: [],
-      uploadPendingIds: ["a"],
-    });
-    expect(out.get("a")).not.toBe("incomplete");
-    expect(out.get("a")).toBe("upload_pending");
-  });
-
-  it("partitions a mixed batch: completed + upload-pending + missing", () => {
-    const out = partitionBatchOutcome(msgs("ok1", "up1", "gone1"), {
       ok: true,
       rows: [
-        { id: "ok1", ai_status: "clean" },
-        // up1 has NO row but IS in uploadPendingIds -> deferred, not failed
+        { id: "a", ai_status: "clean" },
+        { id: "b", ai_status: "flagged" },
       ],
-      uploadPendingIds: ["up1"],
     });
-    expect(out.get("ok1")).toBe("completed");
-    expect(out.get("up1")).toBe("upload_pending");
-    expect(out.get("gone1")).toBe("incomplete"); // unexplained drop stays retryable
+    expect(out.get("a")).toBe("completed");
+    expect(out.get("b")).toBe("completed");
+  });
+
+  it("treats an unexplained missing row as incomplete (retryable)", () => {
+    const out = partitionBatchOutcome(msgs("a", "gone1"), {
+      ok: true,
+      rows: [{ id: "a", ai_status: "clean" }],
+      // gone1 is missing → incomplete
+    });
+    expect(out.get("a")).toBe("completed");
+    expect(out.get("gone1")).toBe("incomplete");
   });
 
   it("routes flag-based failures to their buckets", () => {
@@ -94,17 +76,3 @@ describe("partitionBatchOutcome", () => {
     expect(out.get("r")).toBe("completed");
   });
 });
-
-describe("computeUploadPollDelayMs", () => {
-  it("ramps linearly and respects the cap", () => {
-    expect(computeUploadPollDelayMs(1, 1500, 8000)).toBe(1500);
-    expect(computeUploadPollDelayMs(2, 1500, 8000)).toBe(3000);
-    expect(computeUploadPollDelayMs(3, 1500, 8000)).toBe(4500);
-    expect(computeUploadPollDelayMs(9, 1500, 8000)).toBe(8000); // capped
-  });
-
-  it("is safe on degenerate input", () => {
-    expect(computeUploadPollDelayMs(0, 1500, 8000)).toBe(1500);
-    expect(computeUploadPollDelayMs(-5, 1000, 4000)).toBe(1000);
-  });
-});