fix(android): size owned AVD data partitions

[janicduplessis]

Description

Closes #83. Newly created owned Android AVDs use a measured 8 GiB userdata partition instead of the 10 GiB setting observed on the selected API 36 profile. The 8 GiB candidate retained about 6.24 GiB free after five real dev-client install/relaunch/Metro reload cycles plus a snapshot-disabled cold restart; the 6 GiB emulator floor worked but was deliberately not selected because repeated-install headroom matters.

This does not claim a large reduction in fresh sparse-file du or a proven near-full-disk preflight improvement: measured initial host allocation was nearly identical between 8 GiB and 10 GiB, and no near-full-disk experiment was attempted. It establishes a lower logical userdata growth ceiling while retaining measured development headroom.

Solution

• Add layered android.dataPartitionSizeGb (integer GiB, default 8, range 6–16384).
• Validate invalid values as STIM_CLI_BAD_ARG before device mutation.
• Atomically replace and read back disk.dataPartition.size after avdmanager create and before first boot, using the canonical owned AVD content-directory resolver.
• Mark the device setup incomplete before configuration. Roll back failures through centralized owned-device teardown; if deletion fails, retain the ownership record and require successful cleanup before any retry can recover or boot that AVD.
• Keep creation-collision recovery isolated from post-create configuration failures. Re-read the current same-workspace device record after a collision and refuse recovery when another concurrent run registered it, so stale snapshots cannot boot an incompletely configured AVD.
• Leave recorded and recovered existing AVDs unchanged because Android userdata grows but does not shrink; recreation adopts a changed value.
• Update README, shipped skill, guide output, and contract/unit tests.

A broader safe AVD settings surface is tracked separately in #96; unrestricted replacement config files are intentionally out of scope because they can redirect storage/image paths outside the owned device.

Test plan

• pnpm run format:check
• pnpm run lint
• pnpm run build
• pnpm run typecheck
• pnpm run knip
• pnpm test (2,291 tests)
• pnpm run test:e2e (12 tests)
• Real Android Emulator 36.4.9 / API 36 arm64 16 KB-page image:
  • 10 GiB baseline: first boot 18.962s; about 8.50 GiB free after the representative workflow.
  • 6 GiB boundary: install, launch, navigation, and reload passed; about 4.61 GiB free afterward.
  • 8 GiB candidate: first boot 18.302s; 75 MB Expo dev-client install/launch/navigation/reload passed; five total adb install -r + relaunch + Metro reload cycles passed with about 6.61 GiB free.
  • Snapshot-disabled cold restart took 13.070s; the app persisted, real UI and Metro reload passed, about 6.24 GiB remained free, and host du reached 2,482,948 KiB.
  • All three owned measurement AVDs were centrally deleted; the unrelated user AVD on port 5554 was untouched.