feat: initial model catalog with 196 models across 39 providers

Community-maintained TOML catalog for LibreFang. New models can be added
via PR without requiring a LibreFang binary release.

Includes validation script, bilingual docs, and GitHub templates.

providers/zai-coding.toml

@@ -0,0 +1,35 @@
+# Z.AI Coding / GLM Coding Models — https://api.z.ai
+# Models: 2
+
+[provider]
+id = "zai_coding"
+display_name = "Z.AI Coding"
+api_key_env = "ZHIPU_API_KEY"
+base_url = "https://api.z.ai/api/coding/paas/v4"
+key_required = true
+
+[[models]]
+id = "glm-5-coding"
+display_name = "GLM-5 Coding"
+tier = "frontier"
+context_window = 131072
+max_output_tokens = 16384
+input_cost_per_m = 2.00
+output_cost_per_m = 8.00
+supports_tools = true
+supports_vision = false
+supports_streaming = true
+aliases = ["glm-5-code", "glm-coding"]
+
+[[models]]
+id = "glm-4.7-coding"
+display_name = "GLM-4.7 Coding"
+tier = "smart"
+context_window = 131072
+max_output_tokens = 16384
+input_cost_per_m = 1.50
+output_cost_per_m = 5.00
+supports_tools = true
+supports_vision = false
+supports_streaming = true
+aliases = ["glm-4.7-code"]