v0.2.0 — free provider presets, batch reads, health check, HEIC

What's new in 0.2.0

Free provider presets — one provider switch fills the whole endpoint config:

• zhipu: free GLM-4V-Flash (open.bigmodel.cn) — best default in mainland China
• gemini: free key from Google AI Studio (generativelanguage.googleapis.com/v1beta/openai/)
• dashscope: the default models as a preset
  Explicit fields always override the preset; existing configs (provider unset = custom) are untouched.

Batch image reads — describe_image accepts up to 8 images via images[] in one call (compare screenshots, spot a shared visual family). Single-image cache keys keep the v1 layout, so previously cached answers still hit. One failed image fails the whole call with a clear error.

llm_vision_check diagnostic tool — verifies config, API-key resolution, and a keyed GET /models probe (401/404/network classified), plus an optional end-to-end testCall on a 1×1 image. The API key never appears in the report.

HEIC/HEIF support — the tools read local HEIC/HEIF paths and URLs directly; macOS preprocessing re-encodes them to JPEG (endpoints support HEIC unevenly), and platforms without sips fail loudly instead of shipping a format endpoints reject. The paste/upload channel stays on the official four media types with a hint to use paths instead.

Also: loadImage file-read errors now carry the llm-vision: prefix (error contract), and the attach body cap scales with maxBytes (large-image pastes no longer hit the fixed 16 MiB ceiling).

216 offline tests (was 183), typecheck + CI green.