fix: consolidate provider lists into single CANONICAL_PROVIDERS source of truth (#9237)

Three separate hardcoded provider lists (/model, /provider, hermes model)
diverged over time, causing providers to be missing from some commands.

- Create CANONICAL_PROVIDERS in hermes_cli/models.py as the single source
  of truth for all provider identity, labels, and TUI ordering
- Derive _PROVIDER_LABELS and list_available_providers() from canonical list
- Add step 2b in list_authenticated_providers() to cross-check canonical
  list — catches providers with credentials that weren't found via
  PROVIDER_TO_MODELS_DEV or HERMES_OVERLAYS mappings
- Derive hermes model TUI provider menus from canonical list
- Add deepseek and xai as first-class providers (were missing from TUI)
- Add grok/x-ai/x.ai aliases for xai provider

Fixes: /model command not showing all providers that hermes model shows

hermes_cli/main.py

@@ -1034,29 +1034,9 @@ def select_provider_and_model(args=None):
     if active == "openrouter" and get_env_value("OPENAI_BASE_URL"):
         active = "custom"
 
-    provider_labels = {
-        "openrouter": "OpenRouter",
-        "nous": "Nous Portal",
-        "openai-codex": "OpenAI Codex",
-        "qwen-oauth": "Qwen OAuth",
-        "copilot-acp": "GitHub Copilot ACP",
-        "copilot": "GitHub Copilot",
-        "anthropic": "Anthropic",
-        "gemini": "Google AI Studio",
-        "zai": "Z.AI / GLM",
-        "kimi-coding": "Kimi / Moonshot",
-        "kimi-coding-cn": "Kimi / Moonshot (China)",
-        "minimax": "MiniMax",
-        "minimax-cn": "MiniMax (China)",
-        "opencode-zen": "OpenCode Zen",
-        "opencode-go": "OpenCode Go",
-        "ai-gateway": "AI Gateway",
-        "kilocode": "Kilo Code",
-        "alibaba": "Alibaba Cloud (DashScope)",
-        "huggingface": "Hugging Face",
-        "xiaomi": "Xiaomi MiMo",
-        "custom": "Custom endpoint",
-    }
+    from hermes_cli.models import CANONICAL_PROVIDERS, _PROVIDER_LABELS
+
+    provider_labels = dict(_PROVIDER_LABELS)  # derive from canonical list
     active_label = provider_labels.get(active, active) if active else "none"
 
     print()
@@ -1065,31 +1045,9 @@ def select_provider_and_model(args=None):
     print()
 
     # Step 1: Provider selection — top providers shown first, rest behind "More..."
-    top_providers = [
-        ("nous", "Nous Portal (Nous Research subscription)"),
-        ("openrouter", "OpenRouter (100+ models, pay-per-use)"),
-        ("anthropic", "Anthropic (Claude models — API key or Claude Code)"),
-        ("openai-codex", "OpenAI Codex"),
-        ("qwen-oauth", "Qwen OAuth (reuses local Qwen CLI login)"),
-        ("copilot", "GitHub Copilot (uses GITHUB_TOKEN or gh auth token)"),
-        ("huggingface", "Hugging Face Inference Providers (20+ open models)"),
-    ]
-
-    extended_providers = [
-        ("copilot-acp", "GitHub Copilot ACP (spawns `copilot --acp --stdio`)"),
-        ("gemini", "Google AI Studio (Gemini models — OpenAI-compatible endpoint)"),
-        ("zai", "Z.AI / GLM (Zhipu AI direct API)"),
-        ("kimi-coding", "Kimi / Moonshot (Moonshot AI direct API)"),
-        ("kimi-coding-cn", "Kimi / Moonshot China (Moonshot CN direct API)"),
-        ("minimax", "MiniMax (global direct API)"),
-        ("minimax-cn", "MiniMax China (domestic direct API)"),
-        ("kilocode", "Kilo Code (Kilo Gateway API)"),
-        ("opencode-zen", "OpenCode Zen (35+ curated models, pay-as-you-go)"),
-        ("opencode-go", "OpenCode Go (open models, $10/month subscription)"),
-        ("ai-gateway", "AI Gateway (Vercel — 200+ models, pay-per-use)"),
-        ("alibaba", "Alibaba Cloud / DashScope Coding (Qwen + multi-provider)"),
-        ("xiaomi", "Xiaomi MiMo (MiMo-V2 models — pro, omni, flash)"),
-    ]
+    # Derived from CANONICAL_PROVIDERS (single source of truth)
+    top_providers = [(p.slug, p.tui_desc) for p in CANONICAL_PROVIDERS if p.tier == "top"]
+    extended_providers = [(p.slug, p.tui_desc) for p in CANONICAL_PROVIDERS if p.tier == "extended"]
 
     def _named_custom_provider_map(cfg) -> dict[str, dict[str, str]]:
         custom_provider_map = {}
@@ -1207,7 +1165,7 @@ def select_provider_and_model(args=None):
         _model_flow_anthropic(config, current_model)
     elif selected_provider == "kimi-coding":
         _model_flow_kimi(config, current_model)
-    elif selected_provider in ("gemini", "zai", "kimi-coding-cn", "minimax", "minimax-cn", "kilocode", "opencode-zen", "opencode-go", "ai-gateway", "alibaba", "huggingface", "xiaomi"):
+    elif selected_provider in ("gemini", "deepseek", "xai", "zai", "kimi-coding-cn", "minimax", "minimax-cn", "kilocode", "opencode-zen", "opencode-go", "ai-gateway", "alibaba", "huggingface", "xiaomi"):
         _model_flow_api_key_provider(config, selected_provider, current_model)
 
     # ── Post-switch cleanup: clear stale OPENAI_BASE_URL ──────────────