QVAC-17317 doc: write API ref SDK v0.9.0

[BrunoCampana]

Objective

Create a new API reference for SDK v0.9.0.

Scope

Delta between API v0.8.0 and v0.9.0:

New functions:

• finetune() — Fine-tuning support with three overloads: run (returns FinetuneHandle with progress streaming), stop, and getState
• diffusion() — Image generation via Stable Diffusion models, with progress streaming and DiffusionClientParams (includes SamplingMethod and Scheduler enums)
• suspend() — Suspend the SDK server lifecycle
• resume() — Resume a suspended SDK server
• heartbeat() — Health check with optional delegate parameter, returns HeartbeatResponse
• defineDuplexHandler() — Define bidirectional plugin handlers with request/response schemas

Removed functions:

• ping() — Removed from the public API

Modified functions:

• embed() — Return type changed from Promise<number[]> to Promise<{ embedding: number[]; stats?: EmbedStats }> (and array variant accordingly). New EmbedStats type with totalTime, tokensPerSecond, totalTokens, backendDevice
• completion() — Added backendDevice field ("cpu" | "gpu" | undefined) to CompletionStats

New errors:

• LIFECYCLE_SUSPEND_FAILED (code 53600)
• LIFECYCLE_RESUME_FAILED (code 53601)

Updated error scopes:

• INVALID_RESPONSE_TYPE — Now also thrown by finetune(), heartbeat(), resume(), suspend(); no longer thrown by ping()
• STREAM_ENDED_WITHOUT_RESPONSE — Now also thrown by finetune()

[kinsta]

Preview deployments for qvac-docs-staging ⚡️

Status	Branch preview	Commit preview
✅ Ready	Visit preview	Visit preview

Commit: 6b72de5f90d85d9a08da6aa8830724d6a2379c89

Deployment ID: 809e6501-67e8-4241-a792-28142a6d2063

Static site name: qvac-docs-staging-fazwv

[github-actions]

Tier-based Approval Status

**PR Tier:** TIER1

**Current Status:** ✅ APPROVED

**Requirements:**
- 1 Team Member approval ✅ (1/1)
- 1 Team Lead OR Management approval ✅ (1/1)



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