fix(adb): keep a bare numeric wm density as the physical density (#4074)

Older Android builds print `wm density` as a bare number. The parser's
documentation named that form, but only the labeled `Physical density:`
and `Override density:` lines were matched, so a bare `420` left
`physical_density` null in successful display Evidence with no limitation
saying the declaration was unread (#3942).

The parser now reads the first bare numeric line as the physical density
when no labeled physical declaration is present; a labeled declaration
still wins so a mixed dump cannot downgrade the value. Override density
and physical size are unchanged.

Validation: parser unit tests for the labeled, bare, CRLF, mixed and
unrecognized forms, plus a provider-level regression through the
inspect_adb_display operation; two of them fail on main and pass here.
The issue's three CLI controls through `rea inspect-adb-display` against
a stub adb return physical density 420 for the bare form and keep the
labeled and override controls. Typecheck, lint and module boundaries pass.

Closes #3942

src/adb/AdbProvider.test.ts

@@ -1280,6 +1280,26 @@ it("inspects the display and window focus", async () => {
   );
 });
 
+// Older builds print `wm density` as a bare number; the display projection
+// must keep it as the physical density (morluto/rea#3942).
+it("keeps a bare numeric wm density as the physical density", async () => {
+  const { binary } = await writeAdbStub(
+    shellStub({
+      "wm:size": "Physical size: 1080x2340\n",
+      "wm:density": "420\n",
+    }),
+  );
+  const display = await evidenceResult(providerOver(binary), {
+    operation: "inspect_adb_display",
+    input: { serial: "emulator-5554" },
+  });
+  expect(display).toMatchObject({
+    physical_size: { width: 1080, height: 2340 },
+    physical_density: 420,
+    override_density: null,
+  });
+});
+
 it("reads Android 16 focus declarations from displays when windows omits them", async () => {
   const { binary } = await writeAdbStub(
     shellStub({

src/adb/AdbShellOutput.test.ts

@@ -1,6 +1,49 @@
 import { describe, expect, it } from "vitest";
 
-import { parseAmStartOutput } from "./AdbShellOutput.js";
+import { parseAmStartOutput, parseWmDensityOutput } from "./AdbShellOutput.js";
+
+describe("parseWmDensityOutput", () => {
+  it("reads labeled physical and override densities", () => {
+    expect(
+      parseWmDensityOutput("Physical density: 420\nOverride density: 480\n"),
+    ).toEqual({ physical: 420, override: 480 });
+    expect(parseWmDensityOutput("Physical density: 420\n")).toEqual({
+      physical: 420,
+      override: null,
+    });
+  });
+
+  // Older builds print the physical density as a bare number
+  // (morluto/rea#3942); it must not be lost as an unread declaration.
+  it("reads a bare numeric density as the physical density", () => {
+    expect(parseWmDensityOutput("420\n")).toEqual({
+      physical: 420,
+      override: null,
+    });
+    expect(parseWmDensityOutput("420\r\n")).toEqual({
+      physical: 420,
+      override: null,
+    });
+  });
+
+  it("prefers a labeled physical density over a bare number", () => {
+    expect(parseWmDensityOutput("560\nPhysical density: 420\n")).toEqual({
+      physical: 420,
+      override: null,
+    });
+  });
+
+  it("reports no density for unrecognized output", () => {
+    expect(parseWmDensityOutput("")).toEqual({
+      physical: null,
+      override: null,
+    });
+    expect(parseWmDensityOutput("420dpi\n")).toEqual({
+      physical: null,
+      override: null,
+    });
+  });
+});
 
 const starting =
   "Starting: Intent { act=android.intent.action.MAIN cmp=com.example/.Main }";

src/adb/AdbShellOutput.ts

@@ -125,6 +125,7 @@ const SIZE_PAIR = /^Physical size:\s+(\d+)x(\d+)$/u;
 const SIZE_OVERRIDE = /^Override size:\s+(\d+)x(\d+)$/u;
 const DENSITY_PHYSICAL = /^Physical density:\s+(\d+)$/u;
 const DENSITY_OVERRIDE = /^Override density:\s+(\d+)$/u;
+const DENSITY_BARE = /^(\d+)$/u;
 
 /** Parse `wm size` output into physical and optional override sizes. */
 export const parseWmSizeOutput = (
@@ -153,7 +154,12 @@ export const parseWmSizeOutput = (
   return { physical, override };
 };
 
-/** Parse `wm density` output. Older builds print a bare number. */
+/**
+ * Parse `wm density` output. Current builds print labeled physical and
+ * optional override lines; older builds print the physical density as a
+ * bare number on its own line (morluto/rea#3942). A labeled declaration
+ * wins over a bare one so a mixed dump cannot downgrade the physical value.
+ */
 export const parseWmDensityOutput = (
   stdout: string,
 ): {
@@ -162,14 +168,17 @@ export const parseWmDensityOutput = (
 } => {
   let physical = null;
   let override = null;
+  let bare = null;
   for (const line of stdout.split(/\r?\n/u)) {
     const trimmed = line.trim();
     const physicalMatch = DENSITY_PHYSICAL.exec(trimmed);
     if (physicalMatch !== null) physical = Number(physicalMatch[1]!);
     const overrideMatch = DENSITY_OVERRIDE.exec(trimmed);
     if (overrideMatch !== null) override = Number(overrideMatch[1]!);
+    const bareMatch = DENSITY_BARE.exec(trimmed);
+    if (bareMatch !== null && bare === null) bare = Number(bareMatch[1]!);
   }
-  return { physical, override };
+  return { physical: physical ?? bare, override };
 };
 
 /** Parse focus declarations from `dumpsys window windows` or `displays`. */