Configure Android emulator launch options (headless, GPU, audio, boot animation) from the config file

Standalone task opened by the maintainer; no parent feature.

Scope

The Android driver launches every emulator with a window, the default GPU mode, audio, and the boot animation, and none of it is configurable. Six agents on one Mac get six emulator windows, and a headless Linux CI host cannot boot an emulator at all.

After this PR an operator sets, in ~/.simlock/config.json, how this machine's emulators are launched, the same way ios.slim.* is set for simulators: once, by the operator, and never from a lease request, MCP, or HTTP.

{
  "android": {
    "emulator": {
      "headless": false,      // true adds -no-window
      "gpu": "auto",          // passed as -gpu <mode>; "auto" passes nothing
      "audio": true,          // false adds -no-audio
      "bootAnimation": true   // false adds -no-boot-anim
    }
  }
}

A changed setting applies at a device's next boot; a running emulator keeps the flags it started with. Changing headless or gpu also invalidates a device's clean-baseline snapshot, which the driver rebuilds on the next boot instead of silently degrading every later reclaim to a full wipe. There is no free-form launch-argument escape hatch: only these four keys, so config cannot inject -port, a different AVD home, or anything else that would break containment.

Technical spec

Modules touched

• src/core/config.ts: new android.emulator block beside ios.slim with the defaults above; validators reject a non-boolean headless/audio/bootAnimation and a gpu that is not a non-empty string, naming the key. A gateway warns about and ignores it exactly as it does ios.* (extend the existing gateway-ignored key handling and its docs/CONFIGURATION.md list).
• src/contract/schemas.ts: the config block so simlock config and config.get render it.
• src/daemon/main.ts: thread config.android.emulator into discoverAndroidDriver the way config.ios.slim reaches the iOS driver.
• src/drivers/android/index.ts: AndroidDriverOptions.emulator (optional; defaults equal the config defaults). #startEmulator appends the flags after -no-snapshot-save. #configHash and #currentConfigHash include headless and gpu in the hashed input so the baseline snapshot rebuilds when either changes. audio and bootAnimation do not enter the hash.
• docs/CONFIGURATION.md: the four keys in the table, their validation in the rules paragraph, the "applies at next boot" and snapshot-rebuild notes, and the gateway-ignored list. README.md: no change unless a claim there becomes false.

Contract and event changes

None beyond the config schema. No new operation, event, or lease-request field. lease.request must not gain any of these keys.

Rules in play

• docs/internal/agent-rules/architecture.md: the core hands the block to the driver unread; which emulator flag a key becomes is the driver's business.
• docs/internal/agent-rules/safety.md rule 9: fail closed on config. Only the four named keys, validated at load; no pass-through of arbitrary flags.
• docs/internal/adr/0002-opt-in-slim-ios-simulators.md: the precedent for driver-level, config-only settings.
• docs/internal/agent-rules/testing.md.

Tests

• The default config launches the emulator with the same arguments as before this change (unit, scripted ProcessRunner).
• android.emulator.headless: true adds -no-window to the emulator launch, and audio: false and bootAnimation: false add -no-audio and -no-boot-anim.
• android.emulator.gpu: "swiftshader_indirect" adds -gpu swiftshader_indirect, and "auto" adds nothing.
• A non-boolean android.emulator.headless is rejected at config load, naming the key.
• Changing headless or gpu changes the baseline config hash, so the next boot rebuilds the clean snapshot; changing audio or bootAnimation does not.
• A gateway warns about and ignores android.emulator.*.
• simlock config renders the android.emulator block with its defaults (e2e, fast lane).
• lease.request carrying an android or emulator field is BAD_REQUEST.

Done when

• Every test above passes and pnpm check is green.
• simlock config shows the block; docs/CONFIGURATION.md documents the four keys, the next-boot rule, and the snapshot-rebuild rule.
• The emulator launch command with default config is byte-for-byte what it was before.

Out of scope

• A per-lease or per-request override of any of these keys.
• A free-form launchArgs key.
• An iOS equivalent (simctl boot is already headless; attaching Simulator.app is a separate idea).
• RAM or CPU per emulator; that is capacity's business.

Depends on

Approval

• Approved for delivery

Written by an agent.