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/account-manager/storage.js

@@ -26,12 +26,11 @@ export async function loadAccounts(configPath = ACCOUNT_CONFIG_PATH) {
 
         const accounts = (config.accounts || []).map(acc => ({
             ...acc,
-            isRateLimited: acc.isRateLimited || false,
-            rateLimitResetTime: acc.rateLimitResetTime || null,
             lastUsed: acc.lastUsed || null,
             // Reset invalid flag on startup - give accounts a fresh chance to refresh
             isInvalid: false,
-            invalidReason: null
+            invalidReason: null,
+            modelRateLimits: acc.modelRateLimits || {}
         }));
 
         const settings = config.settings || {};
@@ -69,9 +68,8 @@ export function loadDefaultAccount(dbPath) {
             const account = {
                 email: authData.email || 'default@antigravity',
                 source: 'database',
-                isRateLimited: false,
-                rateLimitResetTime: null,
-                lastUsed: null
+                lastUsed: null,
+                modelRateLimits: {}
             };
 
             const tokenCache = new Map();
@@ -114,10 +112,9 @@ export async function saveAccounts(configPath, accounts, settings, activeIndex)
                 apiKey: acc.source === 'manual' ? acc.apiKey : undefined,
                 projectId: acc.projectId || undefined,
                 addedAt: acc.addedAt || undefined,
-                isRateLimited: acc.isRateLimited,
-                rateLimitResetTime: acc.rateLimitResetTime,
                 isInvalid: acc.isInvalid || false,
                 invalidReason: acc.invalidReason || null,
+                modelRateLimits: acc.modelRateLimits || {},
                 lastUsed: acc.lastUsed
             })),
             settings: settings,