feat: add NVIDIA NIM and MiniMax provider support (#552)

* feat: add NVIDIA NIM and MiniMax provider support

- Add nvidia-nim and minimax to --provider CLI flag
- Add model discovery for NVIDIA NIM (160+ models) and MiniMax
- Update /model picker to show provider-specific models
- Fix provider detection in startup banner
- Update .env.example with new provider options

Supported providers:
- NVIDIA NIM: https://integrate.api.nvidia.com/v1
- MiniMax: https://api.minimax.io/v1

* fix: resolve conflict in StartupScreen (keep NVIDIA/MiniMax + add Codex detection)

* fix: resolve providerProfile conflict (add imports from main, keep NVIDIA/MiniMax)

* fix: revert providerSecrets to match main (NVIDIA/MiniMax handled elsewhere)

* fix: add context window entries for NVIDIA NIM and new MiniMax models

* fix: use GLM-5 as NVIDIA NIM default and MiniMax-M2.5 for consistency

* fix: address remaining review items - add GLM/Kimi context entries, max output tokens, fix .env.example, revert to Nemotron default

* fix: filter NVIDIA NIM picker to chat/instruct models only, set provider-specific API keys from saved profiles

* chore: add more NVIDIA NIM context window entries for popular models

* fix: address remaining non-blocking items - fix base model, clear provider API keys on profile switch

.env.example

@@ -225,6 +225,30 @@ ANTHROPIC_API_KEY=sk-ant-your-key-here
 # GOOGLE_CLOUD_PROJECT=your-gcp-project-id
 
 
+# -----------------------------------------------------------------------------
+# Option 9: NVIDIA NIM
+# -----------------------------------------------------------------------------
+# NVIDIA NIM provides hosted inference endpoints for NVIDIA models.
+# Get your API key from https://build.nvidia.com/
+#
+# CLAUDE_CODE_USE_OPENAI=1
+# NVIDIA_API_KEY=nvapi-your-key-here
+# OPENAI_BASE_URL=https://integrate.api.nvidia.com/v1
+# OPENAI_MODEL=nvidia/llama-3.1-nemotron-70b-instruct
+
+
+# -----------------------------------------------------------------------------
+# Option 10: MiniMax
+# -----------------------------------------------------------------------------
+# MiniMax API provides text generation models.
+# Get your API key from https://platform.minimax.io/
+#
+# CLAUDE_CODE_USE_OPENAI=1
+# MINIMAX_API_KEY=your-minimax-key-here
+# OPENAI_BASE_URL=https://api.minimax.io/v1
+# OPENAI_MODEL=MiniMax-M2.5
+
+
 # =============================================================================
 # OPTIONAL TUNING
 # =============================================================================