feat(automate): make the pipeline builder fully multi-modal (#335)

* feat(shared): add outputModality to Tool metadata for crossing tools

* feat(shared): add modalityForExtension, toolInputModality, toolOutputModality

* fix(pipeline): route finalize and parent jobs to the pipeline's modality pool

* feat(automate): add ConvertAudioControls pipeline step (exemplar)

* feat(automate): add video tool settings controls to pipelines

* feat(automate): add audio tool settings controls to pipelines

* feat(automate): add document tool settings controls to pipelines

* feat(automate): add chart-maker settings control to pipelines

* feat(automate): warn on modality-incompatible pipeline steps

* feat(automate): add single-file download button for pipeline results

* refactor(automate): modality-aware icons, nav handler rename, mobile size bar

* test(pipeline): cover audio, document, file, and cross-modality chains

* i18n(automate): translate the modality-warning tooltip

* test(pipeline): gate media-pool routing assertion on ffmpeg availability

tests/unit/web/pipeline-compat.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from "vitest";
+import { computeStepWarnings } from "@/lib/pipeline-compat";
+
+describe("computeStepWarnings", () => {
+  it("flags an image->video step mismatch", () => {
+    const w = computeStepWarnings(["resize", "trim-video"], "image");
+    expect(w[0]).toBeNull();
+    expect(w[1]).toEqual({ expects: "video", receives: "image" });
+  });
+  it("does not flag a valid cross-modality chain", () => {
+    const w = computeStepWarnings(["extract-audio", "volume-adjust"], "video");
+    expect(w[0]).toBeNull();
+    expect(w[1]).toBeNull();
+  });
+  it("flags the first step against the uploaded file modality", () => {
+    const w = computeStepWarnings(["resize"], "video");
+    expect(w[0]).toEqual({ expects: "image", receives: "video" });
+  });
+  it("does not flag the first step when no file is uploaded yet", () => {
+    expect(computeStepWarnings(["resize"], null)[0]).toBeNull();
+  });
+});