Feat/bankr provider (#888)

* feat(provider): add Bankr LLM Gateway support

Add Bankr as an OpenAI-compatible provider preset with dedicated env vars:
- BNKR_API_KEY, BANKR_BASE_URL, BANKR_MODEL
- Uses X-API-Key header instead of Authorization Bearer
- Base URL: https://llm.bankr.bot/v1
- Default model: claude-opus-4.6

Changes:
- Add 'bankr' to VALID_PROVIDERS and provider flag handling
- Add buildBankrProfileEnv() with env key registration
- Add Bankr detection in startup screen and provider discovery
- Map Bankr env vars to OpenAI-compatible vars in shim
- Add Bankr preset to ProviderManager (alphabetical order)
- Update PRESET_ORDER test to include Bankr

Co-Authored-By: OpenClaude <openclaude@gitlawb.com>

* fixup(provider): address Bankr PR review feedback

1. Map BNKR_API_KEY → OPENAI_API_KEY in providerFlag.ts so
   --provider bankr works with BNKR_API_KEY in non-interactive startup.

2. Remove unconditional BANKR_MODEL read from model.ts; it maps to
   OPENAI_MODEL via providerFlag.ts and openaiShim.ts, preventing
   cross-provider leakage.

3. Use X-API-Key for Bankr model discovery in openaiModelDiscovery.ts
   and providerDiscovery.ts, matching chat request auth.

Co-Authored-By: OpenClaude <openclaude@gitlawb.com>

---------

Co-authored-by: OpenClaude <openclaude@gitlawb.com>

src/utils/providerDiscovery.ts

@@ -197,6 +197,10 @@ export function getLocalOpenAICompatibleProviderLabel(baseUrl?: string): string
     if (host.includes('minimax') || haystack.includes('minimax')) {
       return 'MiniMax'
     }
+    // Check for Bankr LLM gateway
+    if (host.includes('bankr') || haystack.includes('bankr')) {
+      return 'Bankr'
+    }
     // Moonshot AI (Kimi) direct API
     if (host.includes('moonshot') || haystack.includes('moonshot') || haystack.includes('kimi')) {
       return 'Moonshot (Kimi)'
@@ -226,14 +230,16 @@ export async function listOpenAICompatibleModels(options?: {
 }): Promise<string[] | null> {
   const { signal, clear } = withTimeoutSignal(5000)
   try {
+    const baseUrl = getOpenAICompatibleModelsBaseUrl(options?.baseUrl)
+    const isBankr = baseUrl.toLowerCase().includes('bankr')
     const response = await fetch(
-      `${getOpenAICompatibleModelsBaseUrl(options?.baseUrl)}/models`,
+      `${baseUrl}/models`,
       {
         method: 'GET',
         headers: options?.apiKey
-          ? {
-              Authorization: `Bearer ${options.apiKey}`,
-            }
+          ? isBankr
+            ? { 'X-API-Key': options.apiKey }
+            : { Authorization: `Bearer ${options.apiKey}` }
           : undefined,
         signal,
       },