fix(studio): seed a profiled effect on its curve, not at registry defaults

Found in a running studio, which is the only place it could be found: add
a compressor and the module opens reading **Evenness 0.67** with its
make-up gain at 0 dB.

The registry's defaults are not a point on the profile's curve, and
`audioFxProfileStrength` reads the knob back by inverting that curve — so
a default-seeded compressor reports a strength it was never set to, and
every parameter under the knob disagrees with it. That is the
"quieter as you turn it up" failure the measurement pass fixed, arriving
on the very first frame instead.

Adding a profiled effect now seeds it through the profile at 0.5, so the
knob and the mechanism agree from the start. Everything else still
arrives exactly as the registry declares it.

Falsified: restoring the default seed fails the new test. The old
"seeded with its declared defaults" case asserted the behaviour being
fixed, and now uses an effect that has no derived knob — which is what it
was really about.

studio 3696 passing, 18 todo · core 1762.

Author: vanceingalls

packages/studio/src/components/editor/propertyPanelFxSection.test.tsx

@@ -10,6 +10,7 @@ import {
 import { DEFAULT_CARVE } from "@hyperframes/core/audio-carve";
 import { BANDS, EFFECT_COPY, PRESET_PROBLEM } from "@hyperframes/core/audio-fx-copy";
 import { HF_AUDIO_FX_JOBS, HF_AUDIO_FX_JOB_TYPES } from "@hyperframes/core/audio-fx-jobs";
+import { audioFxProfileStrength } from "@hyperframes/core/audio-fx-profiles";
 import { getAudioFxPreset } from "@hyperframes/core/audio-fx-presets";
 
 /**
@@ -218,14 +219,17 @@ describe("FxSection chain", () => {
   });
 
   it("adds an effect seeded with its declared defaults", () => {
+    // An effect with no derived knob arrives exactly as the registry declares
+    // it. The five that DO have one are seeded on their curve instead — see
+    // "adds a profiled effect on its curve" below.
     const { host, onChainChange } = mount();
     click(host.querySelector(".hf-fx-add"));
-    click(byText(host, ".hf-fx-add-item", EFFECT_COPY.compressor?.title ?? ""));
+    click(byText(host, ".hf-fx-add-item", EFFECT_COPY.delay?.title ?? ""));
     expect(onChainChange).toHaveBeenCalledTimes(1);
     const next = onChainChange.mock.calls[0]![0] as HfAudioFxChain;
     expect(next.nodes).toHaveLength(1);
-    expect(next.nodes[0]!.type).toBe("compressor");
-    expect(next.nodes[0]!.params).toEqual(defaultAudioFxParams("compressor"));
+    expect(next.nodes[0]!.type).toBe("delay");
+    expect(next.nodes[0]!.params).toEqual(defaultAudioFxParams("delay"));
   });
 
   it("renders a control for every parameter the effect declares", () => {
@@ -484,6 +488,23 @@ describe("FxSection chain", () => {
     expect(fxCard(host).querySelector(".hf-fx-ruler")).toBeNull();
   });
 
+  it("adds a profiled effect on its curve, not at registry defaults", () => {
+    // The registry's defaults are not a point on the profile's curve, so an
+    // effect seeded with them opened reading a strength it was not set to: a
+    // compressor arrived showing Evenness 0.67 with its make-up gain at 0 dB —
+    // the "quieter as you turn it up" bug the profiles exist to prevent, on the
+    // very first frame. Caught in a running studio, not by these tests.
+    const { host, onChainChange } = mount({ chain: { version: 1, nodes: [] } });
+    click(host.querySelector(".hf-fx-add"));
+    click(byText(host, ".hf-fx-add-item", EFFECT_COPY.compressor?.title ?? ""));
+
+    const written = onChainChange.mock.calls[0]?.[0] as HfAudioFxChain | undefined;
+    const added = written?.nodes[0]?.params ?? {};
+    expect(audioFxProfileStrength("compressor", added)).toBeCloseTo(0.5, 2);
+    // And the mechanism agrees with the knob rather than sitting at its default.
+    expect(added.makeup).not.toBe(defaultAudioFxParams("compressor").makeup);
+  });
+
   it("gives a module with no single real control a derived one", () => {
     // A compressor has seven controls and an author wants one, but no single one
     // of them can be its face: threshold means nothing without ratio. So the

packages/studio/src/components/editor/propertyPanelFxSection.tsx

@@ -26,6 +26,7 @@ import {
   setAudioEqBandGain,
 } from "@hyperframes/core/audio-fx-eq";
 import { EFFECT_COPY } from "@hyperframes/core/audio-fx-copy";
+import { applyAudioFxProfile, getAudioFxProfile } from "@hyperframes/core/audio-fx-profiles";
 import {
   audioFxJobNode,
   HF_AUDIO_FX_JOBS,
@@ -249,13 +250,30 @@ export function FxSection({
     [chain, mutate],
   );
 
-  /** One effect at its defaults, appended — what both adding and auditioning do. */
+  /**
+   * One effect appended, at the values its module opens on.
+   *
+   * For most effects that is the registry's defaults. For the five with a
+   * derived knob it is NOT: the registry defaults are not a point on the
+   * profile's curve, so the module opened reading a strength it was not set to —
+   * a compressor arrived showing Evenness 0.67 with its make-up gain at 0 dB,
+   * which is the "quieter as you turn it up" bug the profiles exist to prevent,
+   * on the very first frame. Seeding through the profile puts the knob and the
+   * mechanism in agreement from the start.
+   */
   const withEffect = useCallback(
     (base: HfAudioFxChain, type: string): HfAudioFxChain => ({
       ...base,
       nodes: [
         ...base.nodes,
-        { type, id: mintAudioFxNodeId(base), enabled: true, params: defaultAudioFxParams(type) },
+        {
+          type,
+          id: mintAudioFxNodeId(base),
+          enabled: true,
+          params: getAudioFxProfile(type)
+            ? applyAudioFxProfile(type, 0.5, defaultAudioFxParams(type))
+            : defaultAudioFxParams(type),
+        },
       ],
     }),
     [],