feat: add z.ai/GLM, Kimi/Moonshot, MiniMax as first-class providers

Adds 4 new direct API-key providers (zai, kimi-coding, minimax, minimax-cn)
to the inference provider system. All use standard OpenAI-compatible
chat/completions endpoints with Bearer token auth.

Core changes:
- auth.py: Extended ProviderConfig with api_key_env_vars and base_url_env_var
  fields. Added providers to PROVIDER_REGISTRY. Added provider aliases
  (glm, z-ai, zhipu, kimi, moonshot). Added auto-detection of API-key
  providers in resolve_provider(). Added resolve_api_key_provider_credentials()
  and get_api_key_provider_status() helpers.
- runtime_provider.py: Added generic API-key provider branch in
  resolve_runtime_provider() — any provider with auth_type='api_key'
  is automatically handled.
- main.py: Added providers to hermes model menu with generic
  _model_flow_api_key_provider() flow. Updated _has_any_provider_configured()
  to check all provider env vars. Updated argparse --provider choices.
- setup.py: Added providers to setup wizard with API key prompts and
  curated model lists.
- config.py: Added env vars (GLM_API_KEY, KIMI_API_KEY, MINIMAX_API_KEY,
  etc.) to OPTIONAL_ENV_VARS.
- status.py: Added API key display and provider status section.
- doctor.py: Added connectivity checks for each provider endpoint.
- cli.py: Updated provider docstrings.

Docs: Updated README.md, .env.example, cli-config.yaml.example,
cli-commands.md, environment-variables.md, configuration.md.

Tests: 50 new tests covering registry, aliases, resolution, auto-detection,
credential resolution, and runtime provider dispatch.

Inspired by PR #33 (numman-ali) which proposed a provider registry approach.
Credit to tars90percent (PR #473) and manuelschipper (PR #420) for related
provider improvements merged earlier in this changeset.

.env.example

@@ -13,6 +13,34 @@ OPENROUTER_API_KEY=
 # Examples: anthropic/claude-opus-4.6, openai/gpt-4o, google/gemini-3-flash-preview, zhipuai/glm-4-plus
 LLM_MODEL=anthropic/claude-opus-4.6
 
+# =============================================================================
+# LLM PROVIDER (z.ai / GLM)
+# =============================================================================
+# z.ai provides access to ZhipuAI GLM models (GLM-4-Plus, etc.)
+# Get your key at: https://z.ai or https://open.bigmodel.cn
+GLM_API_KEY=
+# GLM_BASE_URL=https://api.z.ai/api/paas/v4  # Override default base URL
+
+# =============================================================================
+# LLM PROVIDER (Kimi / Moonshot)
+# =============================================================================
+# Kimi/Moonshot provides access to Moonshot AI coding models
+# Get your key at: https://platform.moonshot.ai
+KIMI_API_KEY=
+# KIMI_BASE_URL=https://api.moonshot.ai/v1  # Override default base URL
+
+# =============================================================================
+# LLM PROVIDER (MiniMax)
+# =============================================================================
+# MiniMax provides access to MiniMax models (global endpoint)
+# Get your key at: https://www.minimax.io
+MINIMAX_API_KEY=
+# MINIMAX_BASE_URL=https://api.minimax.io/v1  # Override default base URL
+
+# MiniMax China endpoint (for users in mainland China)
+MINIMAX_CN_API_KEY=
+# MINIMAX_CN_BASE_URL=https://api.minimaxi.com/v1  # Override default base URL
+
 # =============================================================================
 # TOOL API KEYS
 # =============================================================================