fix(view,place): the boards view pads clear of the phone's navbar

The panel had an inset for this; the calendar never did. Its root filled the
leaf, and Obsidian's phone navbar floats over a leaf rather than shortening
it, so the scroll container ran to the bottom of the screen and the last row
of the list sat under the bar - unreachable.

`lib/inset.ts` is the same pure measurement the panel plugin grew, with the
same tests: the deeper of navbar and keyboard, never their sum, and a bar that
sits beside the view covers nothing of it. The view re-measures by frame until
it holds still and writes `--bcal-inset-bottom`.

`viewport()` subtracts the bar too, so anchored panels and the quick look are
placed against what is actually reachable instead of ending under it.

tests/inset.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, it } from "vitest";
+import { BOTTOM_BARS, insetFor } from "../src/lib/inset";
+import type { Rect } from "../src/lib/inset";
+
+const rect = (over: Partial<Rect> = {}): Rect => ({
+  top: 0,
+  left: 0,
+  right: 390,
+  bottom: 780,
+  height: 780,
+  ...over,
+});
+
+// A phone: 780 tall, a 56px navbar floating over the bottom, 340px of keyboard.
+const NAVBAR = rect({ top: 724, bottom: 780, height: 56 });
+
+describe("insetFor", () => {
+  it("clears nothing when the view stands alone", () => {
+    expect(insetFor(rect(), [], null)).toBe(0);
+  });
+
+  it("clears the navbar that paints over the view", () => {
+    expect(insetFor(rect(), [NAVBAR], null)).toBe(56);
+  });
+
+  it("clears the keyboard, which shortens no layout", () => {
+    expect(insetFor(rect(), [], { height: 440, offsetTop: 0 })).toBe(340);
+  });
+
+  it("takes the deeper of the two rather than their sum", () => {
+    // The navbar hides behind the keyboard while it is up.
+    expect(insetFor(rect(), [NAVBAR], { height: 440, offsetTop: 0 })).toBe(340);
+  });
+
+  it("comes back to the navbar once the keyboard goes", () => {
+    expect(insetFor(rect(), [NAVBAR], { height: 780, offsetTop: 0 })).toBe(56);
+  });
+
+  it("ignores a bar that sits beside the view, not over it", () => {
+    const sidedock = rect({ right: 300 });
+    const statusBar = rect({
+      top: 760,
+      bottom: 780,
+      height: 20,
+      left: 700,
+      right: 980,
+    });
+    expect(insetFor(sidedock, [statusBar], null)).toBe(0);
+  });
+
+  it("measures from where the visible area starts", () => {
+    expect(insetFor(rect(), [], { height: 440, offsetTop: 100 })).toBe(240);
+  });
+
+  it("says nothing about a view with no height yet", () => {
+    expect(insetFor(rect({ height: 0, bottom: 0 }), [NAVBAR], null)).toBe(0);
+  });
+
+  it("never returns a negative inset", () => {
+    const short = rect({ bottom: 300, height: 300 });
+    expect(insetFor(short, [], { height: 780, offsetTop: 0 })).toBe(0);
+  });
+
+  it("names the bars that float rather than make room", () => {
+    expect(BOTTOM_BARS).toContain(".mobile-navbar");
+    expect(BOTTOM_BARS).toContain(".status-bar");
+  });
+});