feat(producer): lower parallel-DE router floor to 700 frames + power-state telemetry

HF_DE_PARALLEL_MIN_FRAMES default 2000 -> 700, re-calibrated by a controlled
crossover sweep (fixed content-per-frame, three synthetic profiles x
{350..3000f} x {single,par2,par3} x 3 reps, resolved worker counts and capture
modes verified per run): par3 beats single at EVERY size in every profile —
+17-21% at 700f rising to +28-34% at 3000f. That includes a
24-sub-composition profile built specifically to reproduce the 'workers
re-pay init' failure the original 2000 floor guarded against (92k tweens,
~2.5s pollSubCompositionTimelines per worker): workers initialize
concurrently, so duplicated init costs CPU, not wall-clock, and the comp
still parallelizes +19% at 700f. Below ~700f the win thins toward +10%
while paying three hardware-GPU browsers, so a floor remains. par2 loses to
par3 in every cell of every profile — the router's existing 3-worker pin is
confirmed, not changed. Harness:
plans/drawelement-fast-capture/de-crossover-bench.sh (docs repo).

Also adds on_battery / low_power_mode to render_complete and render_error.
The DE fleet is macOS laptops, and bench sweeps on an M4 Pro caught the SAME
render flipping between ~9.6 and ~17.2 ms/frame power-management regimes
with no existing telemetry signal to segment by — the router soak reading
this change needs that dimension to interpret perf on the machines users
actually render on. Sampled per event (volatile), pmset-based, darwin-only,
null-safe on failure.

Router stays default-off behind HF_DE_PARALLEL_ROUTER; this tunes what it
will do when the soak clears it to flip.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

packages/cli/src/telemetry/system.test.ts

@@ -110,3 +110,54 @@ describe("getAvailableMemoryMb", () => {
     expect(getAvailableMemoryMb()).toBe(6144);
   });
 });
+
+describe("power state (laptop fleet segmentation)", () => {
+  it("parsePmsetPowerSource reads battery vs AC", async () => {
+    const { parsePmsetPowerSource } = await import("./system.js");
+    expect(parsePmsetPowerSource("Now drawing from 'Battery Power'\n -InternalBattery-0")).toBe(
+      true,
+    );
+    expect(parsePmsetPowerSource("Now drawing from 'AC Power'\n -InternalBattery-0")).toBe(false);
+    expect(parsePmsetPowerSource("garbage output")).toBe(null);
+  });
+
+  it("getPowerState samples pmset on darwin", async () => {
+    vi.doMock("node:os", async () => ({
+      ...(await vi.importActual<typeof import("node:os")>("node:os")),
+      platform: () => "darwin",
+    }));
+    vi.doMock("node:child_process", async () => ({
+      ...(await vi.importActual<typeof import("node:child_process")>("node:child_process")),
+      execSync: (cmd: string) =>
+        cmd === "pmset -g batt"
+          ? "Now drawing from 'Battery Power'\n"
+          : "SleepDisabled 0\n lowpowermode         1\n",
+    }));
+    const { getPowerState } = await import("./system.js");
+    expect(getPowerState()).toEqual({ on_battery: true, low_power_mode: true });
+  });
+
+  it("getPowerState returns nulls off-darwin (no guessing)", async () => {
+    vi.doMock("node:os", async () => ({
+      ...(await vi.importActual<typeof import("node:os")>("node:os")),
+      platform: () => "linux",
+    }));
+    const { getPowerState } = await import("./system.js");
+    expect(getPowerState()).toEqual({ on_battery: null, low_power_mode: null });
+  });
+
+  it("getPowerState survives pmset failure with nulls", async () => {
+    vi.doMock("node:os", async () => ({
+      ...(await vi.importActual<typeof import("node:os")>("node:os")),
+      platform: () => "darwin",
+    }));
+    vi.doMock("node:child_process", async () => ({
+      ...(await vi.importActual<typeof import("node:child_process")>("node:child_process")),
+      execSync: () => {
+        throw new Error("pmset: command failed");
+      },
+    }));
+    const { getPowerState } = await import("./system.js");
+    expect(getPowerState()).toEqual({ on_battery: null, low_power_mode: null });
+  });
+});