Hybrid org context + Servers CRUD

[fbarrento]

What to build

First org-scoped resource. The design's hybrid org-context model lands here for the first time: $forge->org($slug)->... chain override, with an OrganizationNotSetException guard when no org is bound or chained. Implements the full Servers CRUD across the v0.1 surface.

Endpoints (consult docs/forge.openapi.json for the full set, including actions):

• GET /orgs/{org}/servers
• POST /orgs/{org}/servers
• GET /orgs/{org}/servers/{server}
• PATCH /orgs/{org}/servers/{server}
• DELETE /orgs/{org}/servers/{server}
• POST /orgs/{org}/servers/{server}/actions (start, stop, restart, etc.)

Source design: see project_sdk_design.md in the project's memory.

Acceptance criteria

Org context

• $forge->org($slug): Forge returns a new Forge instance bound to that slug (immutable — does not mutate the original)
• Org-scoped resources throw OrganizationNotSetException when neither the constructor nor a chain has set an organization
• Non-org-scoped accessors (me(), organizations(), providers()) keep working regardless of org-context state
• OrganizationNotSetException extends ForgeException (NOT ApiException — this is a client-side guard, not an HTTP error)

Servers slice

• Server output DTO (readonly, JsonSerializable, ::from(array))
• CreateServerData input DTO: required fields per spec (name, provider, region, size, php_version, etc.); enums for closed sets; toArray() strips nulls and converts enums
• UpdateServerData input DTO with all fields optional
• ListServersOptions DTO: pagination + sort + filter[ip_address|name|region|size|provider|ubuntu_version|php_version|database_type]
• Enums: ServerProvider, PhpVersion, DatabaseType, UbuntuVersion (case names match Forge's string values; consult spec)
• Request classes: GetServersRequest, GetServerRequest, CreateServerRequest, UpdateServerRequest, DeleteServerRequest (+ a ServerActionRequest for the /actions endpoint)
• ServersResource: all(?ListServersOptions): Page<Server>, iterate(?ListServersOptions): Generator<Server>, create(CreateServerData): Server
• ServerResource: get(): Server, update(UpdateServerData): Server, delete(): void, plus action methods (e.g. restart(), reboot())
• $forge->servers() and $forge->server($id) wired

Tests

• Each CRUD method round-trips correctly against a MockClient
• $forge->org('other')->servers()->all() hits /api/orgs/other/servers (verifies chain override)
• OrganizationNotSetException thrown when org-scoped methods are called without context
• ListServersOptions::toQuery() emits filter[provider]=aws, sort=-created_at, page[size]=... correctly
• DTO factories (via fbarrento/data-factory) for CreateServerData / UpdateServerData live in tests/Factories/
• composer test green

Blocked by

• Blocked by Providers catalog (read-only) #4