test: update pre-existing stale specs for 2.0 multimodal + validation behavior

Fixes a backlog of integration/unit specs that asserted pre-2.0 behavior and
were failing CI (not caused by recent feature work):
- modality-aware empty-input error is 'No file(s) provided', not /no image/i
  (rotate, border, crop, resize, smart-crop, edge-cases, adversarial-extended,
  api, tool-factory-route)
- input validation rejects pre-enqueue with a clean 400 in 'error' (was a worker
  422 in 'details'): create-zip, extract-zip, merge-csvs
- resolveToolPool defaults unknown tools to the system pool (pool-routing)
- /upload and fetch-urls accept non-image content, validated per-tool at process
  time (api, fetch-urls)
- color-adjust legacy aliases were consolidated into adjust-colors: drop the
  removed-alias tests; retarget the format-preservation tests
- xml-to-csv gracefully converts a single non-repeating record to a 1-row CSV
- dropzone is multimodal; image-only filtering is opt-in via fileFilter
- factory-multi-input: register the synthetic test tools in the catalog so they
  route correctly (file modality for concat; image for the validation-prefix test)

Verified locally: unit 4546 passed, integration 8332 passed, typecheck + lint green.

tests/integration/color-adjustments.test.ts

@@ -3,7 +3,7 @@
  *
  * Covers brightness, contrast, exposure, saturation, hue, temperature, tint,
  * sharpness, channel adjustments, and effects (grayscale, sepia, invert).
- * Also tests legacy alias routes (brightness-contrast, saturation, etc.).
+ * Consolidated adjust-colors tool replaces the old brightness-contrast, saturation, etc.
  */
 
 import { readFileSync } from "node:fs";
@@ -228,37 +228,6 @@ describe("Multiple input formats", () => {
   });
 });
 
-// ── Legacy alias routes ───────────────────────────────────────────
-describe("Legacy alias routes", () => {
-  it("brightness-contrast alias works", async () => {
-    const res = await postTool("brightness-contrast", { brightness: 25, contrast: -10 });
-    expect(res.statusCode).toBe(200);
-    const result = JSON.parse(res.body);
-    expect(result.downloadUrl).toBeDefined();
-  });
-
-  it("saturation alias works", async () => {
-    const res = await postTool("saturation", { saturation: 50 });
-    expect(res.statusCode).toBe(200);
-    const result = JSON.parse(res.body);
-    expect(result.downloadUrl).toBeDefined();
-  });
-
-  it("color-channels alias works", async () => {
-    const res = await postTool("color-channels", { red: 150, green: 50, blue: 100 });
-    expect(res.statusCode).toBe(200);
-    const result = JSON.parse(res.body);
-    expect(result.downloadUrl).toBeDefined();
-  });
-
-  it("color-effects alias works", async () => {
-    const res = await postTool("color-effects", { effect: "sepia" });
-    expect(res.statusCode).toBe(200);
-    const result = JSON.parse(res.body);
-    expect(result.downloadUrl).toBeDefined();
-  });
-});
-
 // ── Error handling ────────────────────────────────────────────────
 describe("Error handling", () => {
   it("returns 400 when no file is provided", async () => {