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/qianfan.toml

@@ -0,0 +1,48 @@
+# Baidu Qianfan / ERNIE — https://qianfan.baidubce.com
+# Models: 3
+
+[provider]
+id = "qianfan"
+display_name = "Baidu Qianfan"
+api_key_env = "QIANFAN_API_KEY"
+base_url = "https://qianfan.baidubce.com/v2"
+key_required = true
+
+[[models]]
+id = "ernie-4.5-8k"
+display_name = "ERNIE 4.5 8K"
+tier = "smart"
+context_window = 8192
+max_output_tokens = 4096
+input_cost_per_m = 2.00
+output_cost_per_m = 6.00
+supports_tools = true
+supports_vision = false
+supports_streaming = true
+aliases = ["ernie"]
+
+[[models]]
+id = "ernie-4.0-turbo-8k"
+display_name = "ERNIE 4.0 Turbo 8K"
+tier = "balanced"
+context_window = 8192
+max_output_tokens = 4096
+input_cost_per_m = 1.00
+output_cost_per_m = 3.00
+supports_tools = true
+supports_vision = false
+supports_streaming = true
+aliases = []
+
+[[models]]
+id = "ernie-speed-128k"
+display_name = "ERNIE Speed 128K"
+tier = "fast"
+context_window = 131072
+max_output_tokens = 4096
+input_cost_per_m = 0.0
+output_cost_per_m = 0.0
+supports_tools = true
+supports_vision = false
+supports_streaming = true
+aliases = []