fix(provider): LM Studio should not be polled by default if unconfigured #28

Summary

LM Studio is polled every 30 seconds by default at http://127.0.0.1:1234 even when the user has never configured it. This generates continuous WARN provider discovery failed log noise and wastes CPU/network on connection attempts that will never succeed.

Root cause

cmd/tinycode/config.go:464 hardcodes a default LM Studio URL:

lmStudioURL := "http://127.0.0.1:1234"

This URL is passed to disc.Start() unconditionally. The only way to stop polling is to add "disabled_providers": ["lm-studio"] to config — an opt-out the user has to discover themselves.

Current workaround

Add to tinycode.jsonc:

{ "disabled_providers": ["lm-studio"] }

This now works (fixed in PR #22 — shouldPoll previously ignored the filter entirely), but requires the user to know about it.

Proposed fix

Change LM Studio (and vLLM) from opt-out to opt-in: only poll if the user has explicitly configured the URL via TINYCODE_LMSTUDIO_HOST env var or a provider.lm-studio config block. If neither is set, lmStudioURL should be "" and discovery skips it entirely.

// Before: always poll
lmStudioURL := "http://127.0.0.1:1234"

// After: only poll if explicitly configured
lmStudioURL := ""
if v := os.Getenv("TINYCODE_LMSTUDIO_HOST"); v != "" {
    lmStudioURL = v
} else if _, ok := cfg.Provider["lm-studio"]; ok {
    lmStudioURL = "http://127.0.0.1:1234" // default only when configured
}

Ollama is different — it's the primary local provider and auto-discovery is a core feature; keep it opt-out.

Acceptance criteria

• No LM Studio polling unless TINYCODE_LMSTUDIO_HOST is set or provider.lm-studio appears in config.
• Same change applied to vLLM (TINYCODE_VLLM_HOST only, no default).
• Existing disabled_providers filter continues to work as a secondary guard.
• No log noise on a clean install with only Ollama running.