Merge main into feat-239-purge-old-reports

2026-07-03 17:25:00 -05:00
parent 9d8581a551 ba2dc7fcf6
commit 5b5e48054d
4 changed files with 370 additions and 35 deletions
@@ -1,6 +1,6 @@
 ---
 name: preflight
-description: Run LibreMail's fast CI gate locally (assembleDebug + testDebugUnitTest + compileDebugAndroidTestKotlin + lintDebug + ktlintCheck + detekt) plus the latest-API-level emulator E2E before pushing or opening a PR. Mirrors the merge gate and runs the highest-API E2E via its Gradle Managed Device; the full multi-API matrix stays CI-only. Use before treating a change as done.
+description: Run LibreMail's fast CI gate locally (assembleDebug + testDebugUnitTest + compileDebugAndroidTestKotlin + lintDebug + ktlintCheck + detekt) plus the top-of-matrix emulator E2E (currently API 35 + 36 via Gradle Managed Devices, then API 37 preview via the hand-provisioning script) before pushing or opening a PR. Mirrors the merge gate; the rest of the multi-API matrix stays CI-only. Use before treating a change as done.
 ---

 # /preflight
@@ -13,12 +13,20 @@ Run the same fast checks CI enforces on every PR, in order, and report the outco
  with a JDK/AGP version mismatch, check `java -version` / `JAVA_HOME` and point it at a 17–21
  JDK (e.g. Android Studio's bundled JBR) before retrying.
 - PowerShell: invoke the wrapper as `.\gradlew`. Git Bash / the Bash tool: `./gradlew`.
- The final E2E step boots an emulator through a Gradle Managed Device, so the host needs
-  hardware acceleration (WHPX on Windows, KVM on Linux, HVF on macOS). Gradle downloads the
-  system image and boots/tears down the AVD itself — no manual emulator setup — but the first
-  run is slow while the image downloads. If the host has no accelerated emulator and the
-  managed device cannot boot, report the E2E step as not run rather than treating the gate as
-  green.
+- The final three E2E steps each boot an emulator, so the host needs a **free hardware
+  hypervisor** (Intel VT-x / AMD-V, exposed as WHPX on Windows, KVM on Linux, HVF on macOS).
+  Shut down VirtualBox, Hyper-V-based VMs, WSL2, Docker Desktop, or any other emulator first — a
+  VM holding the hypervisor starves the AVD, and it hangs at 0% CPU and never reaches
+  `sys.boot_completed`. The api35/api36 steps run through Gradle Managed Devices (Gradle
+  downloads the image and boots/tears down each AVD itself); the api37 step is hand-provisioned
+  by `api37_e2e.py` (see Steps). The first run per API level is slow while its system image
+  downloads. If the host has no accelerated emulator and a device cannot boot, report the E2E
+  step as not run rather than treating the gate as green.
+- The api37 step is a stdlib-only, cross-platform **Python 3** script and needs `python3` plus
+  the Android SDK command-line tools (`sdkmanager`/`avdmanager`) and `emulator` on the machine,
+  located via `ANDROID_SDK_ROOT`/`ANDROID_HOME` (or the per-OS default:
+  `%LOCALAPPDATA%\Android\Sdk` on Windows, `~/Library/Android/sdk` on macOS, `~/Android/Sdk` on
+  Linux). The script installs the preview system image itself on first run.

 ## Steps

@@ -30,7 +38,9 @@ Run these, stopping at the first failure:
 ./gradlew :app:compileDebugAndroidTestKotlin
 ./gradlew :app:lintDebug
 ./gradlew :app:ktlintCheck :app:detekt
-./gradlew :app:api36DebugAndroidTest   # latest-API emulator E2E (highest level in the matrix)
+./gradlew :app:api35DebugAndroidTest   # top-of-matrix emulator E2E (2nd-highest stable level)
+./gradlew :app:api36DebugAndroidTest   # top-of-matrix emulator E2E (highest stable level)
+python3 .claude/skills/preflight/api37_e2e.py   # api37 preview E2E (hand-provisioned; on Windows: py or python)
 ```

 `compileDebugAndroidTestKotlin` compiles the `androidTest` source set — the E2E/instrumented
@@ -44,24 +54,44 @@ merge gate even when the build and lint are green. Add `--continue` to any comma
 `:app:ktlintCheck :app:detekt --continue`) to collect every failure in one pass instead of
 stopping at the first.

-`api36DebugAndroidTest` is last because it is the slowest: it runs the full instrumented/E2E
-suite on `api36` — the highest API level in the E2E matrix — via its Gradle Managed Device,
-which Gradle provisions, boots, and tears down automatically. This one latest-API level is the
-E2E that preflight runs locally and it must pass; CI fans the same suite out across the whole
-API matrix (plus the API 37 preview job). Keep `api36DebugAndroidTest` in lockstep with the
-highest managed device in `app/build.gradle.kts` and the E2E matrix in
-`.github/workflows/ci.yml` — when a newer API level is added there, run that one instead.
+The three E2E steps run last because they are the slowest. `api35DebugAndroidTest` and
+`api36DebugAndroidTest` run the full instrumented/E2E suite on `api35`, then `api36` — the top
+two stable levels in the E2E matrix — each via its own Gradle Managed Device, which Gradle
+provisions, boots, and tears down automatically.
+
+`api37_e2e.py` then runs the same suite on the **API 37 preview** emulator. API 37 has no Gradle
+Managed Device — its only published system image is the nonstandard `android-37.0` /
+`google_apis_ps16k` pairing, which neither `ManagedVirtualDevice`'s `apiLevel` (Int) nor
+`apiPreview` (codename) DSL resolves (see the comment above `testOptions.managedDevices` in
+`app/build.gradle.kts`), so there is no `api37DebugAndroidTest` task. The script hand-provisions
+it essentially the way CI's `e2e-preview` job does — installs the image with `sdkmanager`,
+creates the AVD with `avdmanager`, cold-boots it headless, waits for `sys.boot_completed`, runs
+`:app:connectedDebugAndroidTest`, then kills the emulator and deletes the AVD. The emulator flags
+match `e2e-preview` with one deliberate local exception: the **GPU mode**. CI uses
+`-gpu swiftshader_indirect` (software rendering, deterministic on a headless CI runner); the
+local run uses `-gpu auto-no-window`, which renders on the host GPU — faster, and the mode that
+boots cleanly on a dev machine.
+
+All three levels are the E2E that preflight runs locally and all three must pass; CI fans the
+same suite out across the whole matrix (API 29–36 in `e2e`, plus API 37 in `e2e-preview`). Keep
+`api35DebugAndroidTest` / `api36DebugAndroidTest` in lockstep with the top of the managed-device
+list in `app/build.gradle.kts`, and keep `api37_e2e.py` in lockstep with the `e2e-preview` job in
+`.github/workflows/ci.yml` (same image string + emulator flags, apart from the intentional GPU-mode
+difference noted above) — when a newer API level is added there, run the new top levels instead.

 ## Reporting

- If everything passes, say so plainly (e.g. "preflight green: build, unit tests, lint, ktlint, detekt, api36 E2E").
+- If everything passes, say so plainly (e.g. "preflight green: build, unit tests, lint, ktlint, detekt, api35+api36+api37 E2E").
 - On failure, surface the actual Gradle error and point at the relevant report:
  - unit tests → `app/build/reports/tests/testDebugUnitTest/`
  - lint → `app/build/reports/lint-results-debug.html`
  - ktlint → `app/build/reports/ktlint/` (per source set, e.g. `ktlintTestSourceSetCheck/`)
  - detekt → `app/build/reports/detekt/`
-  - E2E → `app/build/reports/androidTests/managedDevice/` (per-device HTML, e.g. `.../api36/`)
- Run only the **latest-API** E2E here (`api36DebugAndroidTest`, the highest level in the
-  matrix); the full multi-API matrix and the API 37 preview job stay CI's job. If the host has
-  no accelerated emulator and the managed device cannot boot, report that E2E could not run
-  rather than treating the gate as green.
+  - api35/api36 E2E → `app/build/reports/androidTests/managedDevice/` (per-device HTML, e.g.
+    `.../api35/`, `.../api36/`)
+  - api37 E2E → `app/build/reports/androidTests/connected/` (the `connectedDebugAndroidTest`
+    report the script drives); the emulator's own boot log is at the temp path the script prints.
+- Run the **top two stable-API** levels (`api35DebugAndroidTest` + `api36DebugAndroidTest`) plus
+  the **API 37 preview** via `api37_e2e.py`; the rest of the multi-API matrix (API 29–34) stays
+  CI's job. If the host has no accelerated emulator and a device cannot boot (see the hypervisor
+  note in Preconditions), report that E2E could not run rather than treating the gate as green.
@@ -0,0 +1,281 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-3.0-or-later
+"""Hand-provision an API 37 (Android 17, preview) emulator, run LibreMail's instrumented/E2E
+suite against it, then tear the emulator and AVD down. Invoked by the /preflight skill as the
+third (api37) E2E step, alongside the api35/api36 Gradle Managed Devices.
+
+WHY THIS SCRIPT EXISTS
+----------------------
+API 37's only published system image is the nonstandard "android-37.0" / google_apis_ps16k
+(16 KB page size) pairing. AGP's Gradle Managed Device DSL can only build an
+"android-<apiLevel:Int>" package id (apiLevel = 37 -> "android-37") or an
+"android-<apiPreview:codename>" one -- neither resolves to "android-37.0" -- so there is NO
+api37DebugAndroidTest task to run. This script custom-provisions the emulator with
+sdkmanager / avdmanager / emulator directly, closely mirroring CI's `e2e-preview` job in
+.github/workflows/ci.yml (same system image string, same provisioning/boot sequence, same
+emulator flags EXCEPT the GPU mode -- CI uses `-gpu swiftshader_indirect` for headless
+determinism, while this local run uses `-gpu auto-no-window` to render on the host GPU, which
+is faster; see start_emulator). Keep the two in lockstep on everything but that GPU flag: when a
+stable, GMD-compatible API 37 image ships, delete this script, fold api37 into
+testOptions.managedDevices, and fold 37 into CI's `e2e` matrix (dropping the `e2e-preview` job).
+
+Pure standard library, cross-platform (Windows / Linux / macOS): tool paths and executable
+suffixes are resolved per-OS, and `.bat` launchers are wrapped through `cmd /c` on Windows.
+
+HYPERVISOR REQUIREMENT
+----------------------
+The emulator boots with `-accel on`, so it needs a FREE hardware hypervisor (Intel VT-x / AMD-V,
+exposed as WHPX on Windows, KVM on Linux, HVF on macOS). If VirtualBox, Hyper-V, WSL2, Docker
+Desktop, or another emulator is holding it, `-accel on` fails or the AVD hangs at 0% CPU and never
+reaches sys.boot_completed. Shut those down before running preflight.
+
+JDK: the final Gradle step needs a JDK 17-21 daemon (AGP 9.2 fails on JDK 25+), same as the rest
+of preflight -- point JAVA_HOME at a 17-21 JDK before invoking.
+"""
+
+from __future__ import annotations
+
+import argparse
+import os
+import platform
+import subprocess
+import sys
+import tempfile
+import time
+from pathlib import Path
+
+# Defaults mirror .github/workflows/ci.yml e2e-preview (env.API37_IMAGE, env.ANDROID_PLATFORM,
+# env.ANDROID_BUILD_TOOLS) and its avdmanager invocation. Do not diverge without updating ci.yml.
+API37_IMAGE = "system-images;android-37.0;google_apis_ps16k;x86_64"
+PLATFORM_PKG = "platforms;android-37.0"
+BUILD_TOOLS = "build-tools;37.0.0"
+AVD_NAME = "api37"
+DEVICE_PROFILE = "pixel_2"
+BOOT_TIMEOUT = 300
+
+IS_WINDOWS = os.name == "nt"
+BAT = ".bat" if IS_WINDOWS else ""
+EXE = ".exe" if IS_WINDOWS else ""
+
+
+def cmd(tool: str, *args: str) -> list[str]:
+    """Build an argv list, wrapping Windows `.bat`/`.cmd` launchers through `cmd /c`."""
+    if IS_WINDOWS and tool.lower().endswith((".bat", ".cmd")):
+        return ["cmd", "/c", tool, *args]
+    return [tool, *args]
+
+
+def find_sdk_root() -> str:
+    candidates = [os.environ.get("ANDROID_SDK_ROOT"), os.environ.get("ANDROID_HOME")]
+    system = platform.system()
+    if system == "Windows":
+        local = os.environ.get("LOCALAPPDATA")
+        if local:
+            candidates.append(os.path.join(local, "Android", "Sdk"))
+    elif system == "Darwin":
+        candidates.append(os.path.expanduser("~/Library/Android/sdk"))
+    else:
+        candidates.append(os.path.expanduser("~/Android/Sdk"))
+    for candidate in candidates:
+        if candidate and os.path.isdir(candidate):
+            return os.path.abspath(candidate)
+    raise RuntimeError(
+        "Android SDK not found. Set ANDROID_SDK_ROOT (or ANDROID_HOME) to your SDK location."
+    )
+
+
+def resolve_tool(sdk_root: str, rel_paths: list[list[str]], name: str) -> str:
+    for rel in rel_paths:
+        path = os.path.join(sdk_root, *rel)
+        if os.path.isfile(path):
+            return path
+    raise RuntimeError(
+        f"Could not find {name} under {sdk_root}. "
+        "Install the Android SDK command-line tools + emulator."
+    )
+
+
+def run_sdkmanager(sdkmanager: str, args: list[str]) -> None:
+    # Feed a stream of "y" so any unaccepted (incl. preview) license prompt is auto-accepted; this
+    # is the non-interactive equivalent of the CI runner having licenses pre-accepted.
+    result = subprocess.run(cmd(sdkmanager, *args), input="y\n" * 50, text=True, check=False)
+    if result.returncode != 0:
+        raise RuntimeError(f"sdkmanager failed (exit {result.returncode}) for: {' '.join(args)}")
+
+
+def create_avd(avdmanager: str, emulator: str) -> None:
+    print(f"Creating AVD '{AVD_NAME}' from {API37_IMAGE} (device: {DEVICE_PROFILE})...")
+    # "no" answers avdmanager's "create a custom hardware profile?" prompt, mirroring CI.
+    result = subprocess.run(
+        cmd(avdmanager, "create", "avd", "-n", AVD_NAME, "-k", API37_IMAGE,
+            "-d", DEVICE_PROFILE, "--force"),
+        input="no\n", text=True, check=False,
+    )
+    if result.returncode != 0:
+        raise RuntimeError(f"avdmanager create avd failed (exit {result.returncode}).")
+    print("AVDs visible to the emulator:")
+    subprocess.run(cmd(emulator, "-list-avds"), check=False)
+
+
+def start_emulator(emulator: str, emu_log: Path, attempt: int) -> subprocess.Popen:
+    print(f"Starting API 37 emulator (attempt {attempt})...")
+    # Flags mirror .github/workflows/ci.yml e2e-preview (cold headless boot, hardware accel
+    # required, no cameras), with ONE deliberate LOCAL exception -- the GPU mode. CI uses
+    # `-gpu swiftshader_indirect` (software rendering, deterministic on a headless CI runner);
+    # locally we use `-gpu auto-no-window`, which renders on the host GPU: faster, and the mode
+    # that boots cleanly on a dev machine. Keep everything except the GPU mode in lockstep with
+    # that job.
+    flags = [
+        "-avd", AVD_NAME,
+        "-no-window", "-no-audio", "-no-boot-anim", "-no-snapshot", "-accel", "on",
+        "-gpu", "auto-no-window", "-camera-back", "none", "-camera-front", "none",
+    ]
+    log = open(emu_log, "wb")  # noqa: SIM115 - handed to the child; closed in the parent below
+    try:
+        proc = subprocess.Popen(cmd(emulator, *flags), stdout=log, stderr=subprocess.STDOUT)
+    finally:
+        log.close()  # the child has inherited its own fd; the parent's copy is no longer needed
+    return proc
+
+
+def wait_for_boot(adb: str, proc: subprocess.Popen, timeout: int) -> bool:
+    subprocess.run(cmd(adb, "start-server"), check=False)
+    deadline = time.monotonic() + timeout
+
+    # Phase 1 -- the literal `adb wait-for-device`, bounded so a dead emulator can't hang the run
+    # (returns as soon as the emulator registers). Mirrors CI's `adb wait-for-device`.
+    try:
+        subprocess.run(cmd(adb, "wait-for-device"), timeout=max(1, deadline - time.monotonic()),
+                       check=False)
+    except subprocess.TimeoutExpired:
+        return False
+    if proc.poll() is not None:
+        return False
+
+    # Phase 2 -- poll sys.boot_completed until it flips to 1 (mirrors CI's getprop loop).
+    while time.monotonic() < deadline:
+        if proc.poll() is not None:
+            print(f"Emulator process exited during boot (code {proc.returncode}).",
+                  file=sys.stderr)
+            return False
+        out = subprocess.run(cmd(adb, "shell", "getprop", "sys.boot_completed"),
+                             capture_output=True, text=True, check=False)
+        if out.stdout.strip() == "1":
+            return True
+        time.sleep(2)
+    return False
+
+
+def stop_emulator(adb: str | None, proc: subprocess.Popen | None) -> None:
+    if adb:
+        subprocess.run(cmd(adb, "emu", "kill"), check=False,
+                       stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+    time.sleep(2)
+    if proc and proc.poll() is None:
+        proc.terminate()
+        try:
+            proc.wait(timeout=10)
+        except subprocess.TimeoutExpired:
+            proc.kill()
+
+
+def tail(path: Path, lines: int = 80) -> None:
+    try:
+        with open(path, "r", errors="replace") as handle:
+            content = handle.readlines()[-lines:]
+        print("--- emulator.log (tail) ---")
+        print("".join(content))
+    except OSError:
+        pass
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(
+        description="Hand-provision + run the API 37 preview E2E suite.")
+    parser.add_argument("--boot-timeout", type=int, default=BOOT_TIMEOUT,
+                        help="Seconds to wait for the emulator to reach sys.boot_completed.")
+    args = parser.parse_args()
+
+    sdk_root = find_sdk_root()
+    print(f"Using Android SDK at: {sdk_root}")
+    sdkmanager = resolve_tool(sdk_root, [
+        ["cmdline-tools", "latest", "bin", "sdkmanager" + BAT],
+        ["cmdline-tools", "bin", "sdkmanager" + BAT],
+        ["tools", "bin", "sdkmanager" + BAT],
+    ], "sdkmanager")
+    avdmanager = resolve_tool(sdk_root, [
+        ["cmdline-tools", "latest", "bin", "avdmanager" + BAT],
+        ["cmdline-tools", "bin", "avdmanager" + BAT],
+        ["tools", "bin", "avdmanager" + BAT],
+    ], "avdmanager")
+
+    # Pin ANDROID_AVD_HOME so avdmanager (writes it) and the emulator (reads it) agree on the AVD
+    # dir -- the same fix CI's e2e-preview applies to avoid "Unknown AVD name [api37]".
+    avd_home = Path.home() / ".android" / "avd"
+    avd_home.mkdir(parents=True, exist_ok=True)
+    os.environ["ANDROID_AVD_HOME"] = str(avd_home)
+
+    emu_log = Path(tempfile.gettempdir()) / "libremail-api37-emulator.log"
+    adb: str | None = None
+    proc: subprocess.Popen | None = None
+    test_exit = 1
+
+    try:
+        # 1. Install the SDK platform, build-tools, platform-tools, emulator, and preview image.
+        print(f"Installing SDK packages + API 37 preview system image ({API37_IMAGE})...")
+        run_sdkmanager(sdkmanager, ["--licenses"])
+        run_sdkmanager(sdkmanager, [PLATFORM_PKG, BUILD_TOOLS, "platform-tools", "emulator",
+                                    API37_IMAGE])
+
+        # adb + emulator are only guaranteed present after the install above.
+        adb = resolve_tool(sdk_root, [["platform-tools", "adb" + EXE]], "adb")
+        emulator = resolve_tool(sdk_root, [["emulator", "emulator" + EXE]], "emulator")
+
+        # 2. Create the AVD, mirroring CI.
+        create_avd(avdmanager, emulator)
+
+        # 3. Cold-boot headless, retrying once (mirrors CI's two-attempt boot loop).
+        booted = False
+        for attempt in (1, 2):
+            proc = start_emulator(emulator, emu_log, attempt)
+            if wait_for_boot(adb, proc, args.boot_timeout):
+                booted = True
+                break
+            print(f"API 37 emulator did not boot within {args.boot_timeout}s (attempt {attempt}).",
+                  file=sys.stderr)
+            tail(emu_log)
+            stop_emulator(adb, proc)
+            proc = None
+            time.sleep(5)
+        if not booted:
+            raise RuntimeError("API 37 preview emulator failed to boot after 2 attempts.")
+
+        # 4. Dismiss the keyguard, then run the instrumented/E2E suite against the booted emulator.
+        subprocess.run(cmd(adb, "shell", "input", "keyevent", "82"), check=False)
+
+        repo_root = Path(__file__).resolve().parents[3]
+        gradlew = repo_root / ("gradlew.bat" if IS_WINDOWS else "gradlew")
+        print(f"Running :app:connectedDebugAndroidTest against {AVD_NAME}...")
+        test_exit = subprocess.run(
+            cmd(str(gradlew), ":app:connectedDebugAndroidTest", "--stacktrace"),
+            cwd=str(repo_root), check=False,
+        ).returncode
+    except Exception as exc:  # noqa: BLE001 - top-level guard so teardown always runs
+        print(f"ERROR: {exc}", file=sys.stderr)
+        test_exit = 1
+    finally:
+        # 5. Always tear the emulator down and delete the AVD, even on failure.
+        print("Tearing down API 37 emulator and AVD...")
+        stop_emulator(adb, proc)
+        subprocess.run(cmd(avdmanager, "delete", "avd", "-n", AVD_NAME), check=False,
+                       stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+
+    if test_exit != 0:
+        print(f"api37 connectedDebugAndroidTest failed (exit {test_exit}).", file=sys.stderr)
+        return test_exit
+    print("api37 E2E passed.")
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())
@@ -28,15 +28,22 @@ or via Gradle Managed Devices `./gradlew e2eGroupDebugAndroidTest` (whole matrix

 **Before treating a change as done**, run the fast CI gate: `assembleDebug` +
 `testDebugUnitTest` + `compileDebugAndroidTestKotlin` + `lintDebug` + `ktlintCheck` +
-`detekt` + the latest-API emulator E2E `api36DebugAndroidTest` (the `/preflight` skill does
-all of this). `compileDebugAndroidTestKotlin` compiles the `androidTest` source set that the
-static part of the gate skips, catching E2E/instrumented-test compile errors before they
-surface only in CI. `ktlintCheck`/`detekt` cover the `test`/`androidTest` source sets that
-`lintDebug` skips, so they catch style violations that would otherwise fail CI's Static
-analysis gate. `api36DebugAndroidTest` runs the instrumented/E2E suite on API 36 — the highest
-API level in the E2E matrix — via its Gradle Managed Device (Gradle boots and tears down the
-emulator automatically). Running that one latest-API level locally is required; the full
-multi-API matrix (and the API 37 preview job) stays CI's job.
+`detekt` + the top-of-matrix emulator E2E `api35DebugAndroidTest` + `api36DebugAndroidTest` +
+the API 37 preview E2E via `python3 .claude/skills/preflight/api37_e2e.py` (the `/preflight`
+skill does all of this). `compileDebugAndroidTestKotlin` compiles the `androidTest` source set
+that the static part of the gate skips, catching E2E/instrumented-test compile errors before
+they surface only in CI. `ktlintCheck`/`detekt` cover the `test`/`androidTest` source sets that
+`lintDebug` skips, so they catch style violations that would otherwise fail CI's Static analysis
+gate. `api35DebugAndroidTest` and `api36DebugAndroidTest` run the instrumented/E2E suite on the
+top two stable API levels in the E2E matrix, each via its own Gradle Managed Device (Gradle boots
+and tears down each emulator automatically). API 37 (preview) has no Gradle Managed Device — its
+only image is the nonstandard `android-37.0` / `google_apis_ps16k` pairing (see the comment above
+`testOptions.managedDevices` in `app/build.gradle.kts`) — so `api37_e2e.py` hand-provisions it,
+mirroring CI's `e2e-preview` job (same image + emulator flags, except it uses host-GPU
+`-gpu auto-no-window` locally vs CI's headless `-gpu swiftshader_indirect`), boots it headless,
+runs `connectedDebugAndroidTest`, and tears it down. Running all three levels locally is required; the
+rest of the multi-API matrix (API 29–34) stays CI's job. Emulators need a free hardware
+hypervisor (VT-x/WHPX), so shut down VirtualBox/other VMs first or the AVD hangs at 0% CPU.

 ## Build-config gotchas

@@ -70,9 +77,11 @@ pulled in as a real dependency for unit tests because `android.jar`'s version is
 A change is not done until it ships with passing **unit tests** and **E2E/instrumented tests**
 that exercise the new or changed behaviour. Writing and committing that E2E/instrumented test
 is a required part of every task — and the test must actually **run and pass**, not merely
-compile: preflight runs the latest-API-level emulator E2E locally (`api36DebugAndroidTest`, the
-highest API level in the E2E matrix and its Gradle Managed Device task) and it must be green
-before the change is done. CI then runs the full multi-API matrix.
+compile: preflight runs the top-of-matrix emulator E2E locally — `api35DebugAndroidTest` +
+`api36DebugAndroidTest` (Gradle Managed Devices) plus the API 37 preview via
+`api37_e2e.py` (hand-provisioned, mirroring CI's `e2e-preview` job) — and all three must be
+green before the change is done. CI then runs the full multi-API matrix plus the API 37 preview
+job.

 ## Repo etiquette

@@ -146,8 +146,23 @@ android {
        // `./gradlew api29DebugAndroidTest`. Gradle provisions/boots/tears down the emulators and
        // downloads the system images on first use. Keep this list in lockstep with the CI matrix in
        // .github/workflows/ci.yml; when a new Android ships, add it and drop the oldest level that
-        // has fallen outside ~7 years. API 37 (preview) is exercised on the dev emulator until a
-        // stable managed-device image is published, so it is intentionally not listed here.
+        // has fallen outside ~7 years.
+        //
+        // API 37 (preview) is intentionally NOT listed here (re-confirmed 2026-07, see PR that added
+        // API 35/37 to preflight): its only published system image is the nonstandard
+        // "android-37.0" / google_apis_ps16k pairing that the e2e-preview job in
+        // .github/workflows/ci.yml installs directly via sdkmanager. ManagedVirtualDevice only knows
+        // how to build an "android-<apiLevel:Int>" package id (e.g. `apiLevel = 37` → "android-37")
+        // or an "android-<apiPreview:codename>" one — neither produces "android-37.0" — so there is
+        // no DSL path to this image today, the same root cause documented on e2e-preview for why
+        // reactivecircus/android-emulator-runner can't provision it either. issue #124's perf doc
+        // (docs/perf/issue-124-unified-inbox-paging.md) independently corroborates this: its API 37
+        // cross-check used a physical Pixel, not an emulator/AVD. Locally, preflight covers API 37
+        // by hand-provisioning it with .claude/skills/preflight/api37_e2e.py, which mirrors the
+        // e2e-preview job (same image + emulator flags, except it renders on the host GPU via
+        // `-gpu auto-no-window` locally instead of CI's headless `-gpu swiftshader_indirect`). Once
+        // a managed-device-compatible image is published, add `api37` here (and to the CI matrix),
+        // delete that script, and drop the e2e-preview job.
        managedDevices {
            localDevices {
                listOf(29, 30, 31, 32, 33, 34, 35, 36).forEach { api ->