refactor: notify/footer 持久配置收编到 config/，chrome bridge 地址固定

仓库规则要求 config/ 为唯一配置来源、不以环境变量作持久默认值：
- pi-notify 改读 config/pi-notify.json（逐字段校验回退，复用原 parsers 钳制）
- pi-minimal-footer 改读 config/pi-minimal-footer.json
- pi-chrome 移除 PI_CHROME_BRIDGE_HOST/PORT，固定 127.0.0.1:17318
  （浏览器端 service_worker.js 硬编码同一地址，单侧可配只会断连）

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Co-Authored-By: Devin <158243242+devin-ai-integration[bot]@users.noreply.github.com>

pi-notify/tests/settings.test.ts

@@ -0,0 +1,107 @@
+import assert from "node:assert/strict";
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, it } from "node:test";
+import { readNotifySettings } from "../src/settings.ts";
+
+let tempDir: string | undefined;
+
+afterEach(() => {
+  if (tempDir) {
+    rmSync(tempDir, { recursive: true, force: true });
+    tempDir = undefined;
+  }
+});
+
+function configPath(contents: string): string {
+  tempDir = mkdtempSync(join(tmpdir(), "pi-notify-settings-"));
+  const path = join(tempDir, "pi-notify.json");
+  writeFileSync(path, contents);
+  return path;
+}
+
+const expectedDefaults = {
+  enabled: true,
+  title: "π - {project}",
+  body: "{message}",
+  messageSource: "assistant",
+  messageMax: 80,
+  minDurationMs: 3_000,
+  visibility: "always",
+  action: "focus",
+  soundCommand: undefined,
+};
+
+describe("readNotifySettings", () => {
+  it("returns all defaults when the config file is missing", () => {
+    assert.deepEqual(readNotifySettings("/does/not/exist/pi-notify.json"), expectedDefaults);
+  });
+
+  it("returns all defaults for malformed or non-object JSON", () => {
+    for (const contents of ["not json", "[1,2]", "\"hi\"", "42"]) {
+      assert.deepEqual(readNotifySettings(configPath(contents)), expectedDefaults, contents);
+    }
+  });
+
+  it("adopts valid values from the config file", () => {
+    const settings = readNotifySettings(configPath(JSON.stringify({
+      enabled: false,
+      title: "π {status_icon} · {project}",
+      body: "{status}",
+      messageSource: "none",
+      messageMax: 120,
+      minSeconds: 30,
+      visibility: "unfocused",
+      action: "none",
+      soundCommand: "afplay /done.aiff",
+    })));
+
+    assert.deepEqual(settings, {
+      enabled: false,
+      title: "π {status_icon} · {project}",
+      body: "{status}",
+      messageSource: "none",
+      messageMax: 120,
+      minDurationMs: 30_000,
+      visibility: "unfocused",
+      action: "none",
+      soundCommand: "afplay /done.aiff",
+    });
+  });
+
+  it("falls back per-field when values have the wrong type or value", () => {
+    const settings = readNotifySettings(configPath(JSON.stringify({
+      enabled: {},
+      title: "",
+      body: null,
+      messageSource: ["assistant"],
+      messageMax: "bogus",
+      minSeconds: "bogus",
+      visibility: "bogus",
+      action: {},
+    })));
+
+    assert.deepEqual(settings, expectedDefaults);
+  });
+
+  it("clamps messageMax and minSeconds to their bounded ranges", () => {
+    const settings = readNotifySettings(configPath(JSON.stringify({ messageMax: 999, minSeconds: 4000 })));
+    assert.equal(settings.messageMax, 500);
+    assert.equal(settings.minDurationMs, 3_600_000);
+
+    const floor = readNotifySettings(configPath(JSON.stringify({ messageMax: -5, minSeconds: -1 })));
+    assert.equal(floor.messageMax, 0);
+    assert.equal(floor.minDurationMs, 0);
+  });
+
+  it("treats an empty or whitespace soundCommand as absent and trims values", () => {
+    for (const value of ["", "   "]) {
+      assert.equal(readNotifySettings(configPath(JSON.stringify({ soundCommand: value }))).soundCommand, undefined);
+    }
+    assert.equal(
+      readNotifySettings(configPath(JSON.stringify({ soundCommand: "  afplay /done.aiff  " }))).soundCommand,
+      "afplay /done.aiff",
+    );
+  });
+});