Add sandbox snapshot support to the TypeScript SDK - #284

## Summary

Brings the Go CLI to parity with the TypeScript SDK (#284) on
fork-from-snapshot: `amika sandbox create --snapshot <slug>` now boots a
remote sandbox from a captured snapshot. Part of the parity audit
(KAPRO-570).

## Changes

- **`apiclient.CreateSandboxRequest`** — new `Snapshot *string` field
  (`json:"snapshot,omitempty"`). nil omits the field (server keeps its
  default snapshot chain); a slug forks the new sandbox from that
  snapshot.
- **`--snapshot` flag** on `sandbox create`, gated to `--remote` mode
  (mirrors the existing `--github-auth-mode` guard) — the local Docker /
  OSS `/v1` path has no cloud-snapshot store.
- Docs (`cli-reference.md`) + tests.

## Testing

Ran with Go 1.25.3 against the affected packages:

- `gofmt -l` clean · `go build ./...` OK · `go vet` OK
- `go test ./internal/apiclient/... ./cmd/amika/...` — pass
- New tests: `TestCreateSandboxSnapshotField` (slug sent / nil omitted),
`TestSandboxCreateHasSnapshotFlag`,
`TestSandboxCreateSnapshotRequiresRemote`

## Known limitation

`*string` + `omitempty` can't encode the server's explicit-`null`
opt-out (the repo-default bypass the TS SDK's `snapshot: null` exposes):
nil omits the field rather than sending `null`. Supporting it would need
a custom nullable type — out of scope here, since the CLI's need is
"fork from a slug." Called out in a comment on the field.

---------

Co-authored-by: Jakub Cichon <jakub@amika.dev>

Release sdk-typescript@v0.10.0.

Changes since sdk-typescript@v0.9.3:
- Add sandbox snapshot support to the TypeScript SDK (#284) (663909e)
- Document AgentCredentialRef resolution rules in TS SDK (#267) (aa784c2)

Release `amika@v0.12.0` by bumping `DEFAULT_VERSION` in `install.sh`
from `0.11.2` to `0.12.0`.

## Changes since amika@v0.11.2

**Sandbox & CLI:**
- Add top-level `amika scp` command for SSH file copy (#278)
- Add `amika snapshot create/list/delete` commands (#282)
- Add `--snapshot` flag to `amika sandbox create` (#285)
- Support remote mode in `service list` (#283)
- Add (then hide) the `--github-auth-mode` flag on `sandbox create`
(#270, #273)
- Show command aliases in `amika` CLI help output (#263)

**Sandbox images & VM snapshots:**
- Install amika and amikalog CLIs in sandbox images (#280)
- Auto-install amikalog hooks in sandbox images (#281)
- Bump L/XL sandbox disk to 24 GB / 32 GB (#279)
- Match VM snapshot sizes to container sizes; add XL (#272)
- Version linux-vm snapshots by git short hash (#276)
- Don't publish the xs VM snapshot for coder-dind (#275)
- Publish Daytona linux-vm snapshots and restore setuid on VM boot
(#271)
- Drop user@host line from sandbox shell prompt (#269)
- Clear stale dockerd pidfile before starting daemon (#268)

**TypeScript SDK:**
- Release TypeScript SDK v0.10.0 with sandbox snapshot support (#287,
#284)
- Add `*.functional.test.ts` convention and prod guard (#286)
- Document AgentCredentialRef resolution rules (#267)

**Docs & internal:**
- Keep README local-first and add Amika Cloud section (#260)
- Fix stale API route paths in CLI client comments (#264)

Bumps [pnpm/action-setup](https://github.com/pnpm/action-setup) from 5.0.0 to 6.1.0.

## Release notes

Sourced from pnpm/action-setup's releases.

### v6.1.0

### What's Changed
- feat: support pnpm v12 by `@zkochan` in pnpm/action-setup#288

Full Changelog: pnpm/action-setup@v6.0.10...v6.1.0

### v6.0.10

### What's Changed
- docs(README): point users to the successor pnpm/setup action by `@BlackHole1` in pnpm/action-setup#282
- refactor: introduce restore keys for cache by `@SukkaW` in pnpm/action-setup#280
- ci: use pnpm 11 for `pr-check` by `@jamietanna` in pnpm/action-setup#284
- fix: update pnpm to v11.19.0 by `@jamietanna` in pnpm/action-setup#283
- docs: update README to include devEngines.packageManager by `@nemchik` in pnpm/action-setup#273

### New Contributors
- `@jamietanna` made their first contribution in pnpm/action-setup#284
- `@nemchik` made their first contribution in pnpm/action-setup#273

Full Changelog: pnpm/action-setup@v6...v6.0.10

### v6.0.9

### What's Changed
- fix: update pnpm to v11.7.0 by `@zkochan` in pnpm/action-setup#267

Full Changelog: pnpm/action-setup@v6...v6.0.9

### v6.0.8

### What's Changed
- docs(README): fix `cache_dependency_path` type by `@haines` in pnpm/action-setup#257
- fix: drop patchPnpmEnv so standalone+self-update works on Windows by `@zkochan` in pnpm/action-setup#258
- fix: update pnpm to 11.1.1 by `@mungodewar` in pnpm/action-setup#248

### New Contributors
- `@mungodewar` made their first contribution in pnpm/action-setup#248

Full Changelog: pnpm/action-setup@v6.0.7...v6.0.8

### v6.0.7

### What's Changed
- fix: honor devEngines.packageManager.onFail=error (#252) by `@zkochan` in pnpm/action-setup#254
- fix: restore inputs from state in post by `@haines` in pnpm/action-setup#255
- fix: self-update bootstrap to packageManager-pinned version (#233) by `@zkochan` in pnpm/action-setup#256

### New Contributors
- `@haines` made their first contribution in pnpm/action-setup#255

Full Changelog: pnpm/action-setup@v6.0.6...v6.0.7

... (truncated)

## Commits
- `ea17c68` feat: support pnpm v12 (#288)
- `0977fd9` docs: Update README to include devEngines.packageManager (#273)
- `48261ac` fix: update pnpm to v11.19.0 (#283)
- `75677f7` ci: use pnpm 11 for `pr-check` (#284)
- `769ae71` refactor: introduce restore keys for cache (#280)
- `6fed91f` docs(README): point users to the successor pnpm/setup action (#282)
- `0ebf471` fix: update pnpm to v11.7.0 (#267)
- `0e279bb` fix: update pnpm to 11.1.1 (#248)
- `3e83581` fix: drop patchPnpmEnv so standalone+self-update works on Windows (#258)
- `551b42e` docs(README): fix `cache_dependency_path` type (#257)
- Additional commits viewable in compare view