Selective fixes from PR #35: Model-specific rate limits & robustness improvements (#37)

* feat: apply local user changes and fixes

* ;D

* Implement OpenAI support, model-specific rate limiting, and robustness fixes

* docs: update pr title

* feat: ensure unique openai models endpoint

* fix: startup banner alignment and removed duplicates

* feat: add model fallback system with --fallback flag

* fix: accounts cli hanging after completion

* feat: add exit option to accounts cli menu

* fix: remove circular dependency warning for fallback flag

* feat: show active modes in banner and hide their flags

* Remove OpenAI compatibility and fallback features from PR #35

Cherry-picked selective fixes from PR #35 while removing:
- OpenAI-compatible API endpoints (/openai/v1/*)
- Model fallback system (fallback-config.js)
- Thinking block skip for Gemini models
- Unnecessary files (pullrequest.md, test-fix.js, test-openai.js)

Retained improvements:
- Network error handling with retry logic
- Model-specific rate limiting
- Enhanced health check with quota info
- CLI fixes (exit option, process.exit)
- Startup banner alignment (debug mode only)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* banner alignment fix

* Refactor: Model-specific rate limits and cleanup deprecated code

- Remove global rate limit fields (isRateLimited, rateLimitResetTime) in favor of model-specific limits (modelRateLimits[modelId])
- Remove deprecated wrapper functions (is429Error, isAuthInvalidError) from handlers
- Filter fetchAvailableModels to only return Claude and Gemini models
- Fix getCurrentStickyAccount() to pass model param after waiting
- Update /account-limits endpoint to show model-specific limits
- Remove multi-account OAuth flow to avoid state mismatch errors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* fix: show (x/y) limited status in account-limits table

- Status is now "ok" only when all models are available
- Shows "(x/y) limited" when x out of y models are exhausted
- Provides better visibility into partial rate limiting

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* docs: update CLAUDE.md with model-specific rate limiting

- Document modelRateLimits[modelId] for per-model rate tracking
- Add isNetworkError() helper to utilities section

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: M1noa <minoa@minoa.cat>
Co-authored-by: Minoa <altgithub@minoa.cat>
Co-authored-by: Claude <noreply@anthropic.com>

src/format/request-converter.js

@@ -152,6 +152,16 @@ export function convertAnthropicToGoogle(anthropicRequest) {
             if (thinkingBudget) {
                 thinkingConfig.thinking_budget = thinkingBudget;
                 logger.debug(`[RequestConverter] Claude thinking enabled with budget: ${thinkingBudget}`);
+
+                // Validate max_tokens > thinking_budget as required by the API
+                const currentMaxTokens = googleRequest.generationConfig.maxOutputTokens;
+                if (currentMaxTokens && currentMaxTokens <= thinkingBudget) {
+                    // Bump max_tokens to allow for some response content
+                    // Default to budget + 8192 (standard output buffer)
+                    const adjustedMaxTokens = thinkingBudget + 8192;
+                    logger.warn(`[RequestConverter] max_tokens (${currentMaxTokens}) <= thinking_budget (${thinkingBudget}). Adjusting to ${adjustedMaxTokens} to satisfy API requirements`);
+                    googleRequest.generationConfig.maxOutputTokens = adjustedMaxTokens;
+                }
             } else {
                 logger.debug('[RequestConverter] Claude thinking enabled (no budget specified)');
             }