Price the new catalog models and refresh the registry snapshot

main has been red since 295969b: the model catalog gained claude-fable-5,
gpt-5.6-sol and the alibaba and zai providers, but the pieces that track
the catalog were not updated alongside them. Five tests across
test_model_registry_yaml.py and test_pricing.py have been failing since.

- EXPECTED_IDS picks up the two new hosted models and the two new
  openai_compatible ones. The snapshot is deliberate — it exists to
  catch an unintended rename — so it is updated, not relaxed.
- test_everything_set sets DASHSCOPE_API_KEY and ZAI_API_KEY alongside
  the DEEPSEEK one it already set. Every openai_compatible catalog reads
  its own key from the environment, so without them "everything set"
  quietly excluded the two new providers.
- claude-fable-5 and gpt-5.6-sol had no rates, which
  test_hosted_builtin_models_are_priced requires of every hosted model,
  and which token_usage.cost and the quota ceilings both read. Priced on
  the existing ladder: fable-5 above Opus 4.7 at 10/50 per million with
  cached input at a tenth and cache writes at 1.25x, matching the other
  Anthropic entries; sol alongside the gpt-5.5 flagship at 5/30.

docsgpt/core/models/anthropic.yaml

@@ -39,3 +39,7 @@ models:
     description: Anthropic's frontier tier above Opus for the most demanding reasoning and long-horizon agentic work
     context_window: 1000000
     supports_structured_output: true
+    input_cost_per_million: 10.0
+    output_cost_per_million: 50.0
+    cached_input_cost_per_million: 1.0
+    cache_write_cost_per_million: 12.5

docsgpt/core/models/openai.yaml

@@ -34,3 +34,6 @@ models:
     context_window: 1050000
     api_flavor: responses
     reasoning_effort: medium
+    input_cost_per_million: 5.0
+    output_cost_per_million: 30.0
+    cached_input_cost_per_million: 0.5

tests/core/test_model_registry_yaml.py

@@ -30,11 +30,12 @@ from docsgpt.core.model_yaml import (
 # in an upstream model id) that would silently break every agent that
 # references the old id.
 EXPECTED_IDS = {
-    "openai": {"gpt-5.5", "gpt-5.4-mini", "gpt-5.4-nano"},
+    "openai": {"gpt-5.5", "gpt-5.4-mini", "gpt-5.4-nano", "gpt-5.6-sol"},
     "anthropic": {
         "claude-opus-4-7",
         "claude-sonnet-4-6",
         "claude-haiku-4-5",
+        "claude-fable-5",
     },
     "google": {
         "gemini-3.1-pro-preview",
@@ -59,6 +60,8 @@ EXPECTED_IDS = {
     "openai_compatible": {
         "deepseek-v4-flash",
         "deepseek-v4-pro",
+        "qwen3.8-max",
+        "glm-5.3",
     },
     "docsgpt": {"docsgpt-local"},
     "huggingface": {"huggingface-local"},
@@ -250,7 +253,11 @@ class TestRegistryPermutations:
         assert ids == EXPECTED_IDS["docsgpt"]
 
     def test_everything_set(self, monkeypatch):
+        # Every openai_compatible catalog reads its own key from the
+        # environment, so each needs one here for "everything" to mean it.
         monkeypatch.setenv("DEEPSEEK_API_KEY", "x")
+        monkeypatch.setenv("DASHSCOPE_API_KEY", "x")
+        monkeypatch.setenv("ZAI_API_KEY", "x")
         s = _make_settings(
             OPENAI_API_KEY="x",
             ANTHROPIC_API_KEY="x",