feat(config): add per-auth disable_cooling override support

- Introduced `disable_cooling` metadata field for fine-grained control over cooldown scheduling.
- Updated `Auth` object to include `Metadata` with conditional logic for handling empty states.
- Added YAML configuration support for `disable_cooling` in API key definitions across providers.
- Enhanced unit tests to validate `disable_cooling` behavior in various scenarios.

internal/watcher/synthesizer/config.go

@@ -60,6 +60,10 @@ func (s *ConfigSynthesizer) synthesizeGeminiKeys(ctx *SynthesisContext) []*corea
 			"source":  fmt.Sprintf("config:gemini[%s]", token),
 			"api_key": key,
 		}
+		metadata := map[string]any{}
+		if entry.DisableCooling {
+			metadata["disable_cooling"] = true
+		}
 		if entry.Priority != 0 {
 			attrs["priority"] = strconv.Itoa(entry.Priority)
 		}
@@ -78,10 +82,14 @@ func (s *ConfigSynthesizer) synthesizeGeminiKeys(ctx *SynthesisContext) []*corea
 			Status:     coreauth.StatusActive,
 			ProxyURL:   proxyURL,
 			Attributes: attrs,
+			Metadata:   metadata,
 			CreatedAt:  now,
 			UpdatedAt:  now,
 		}
 		ApplyAuthExcludedModelsMeta(a, cfg, entry.ExcludedModels, "apikey")
+		if len(a.Metadata) == 0 {
+			a.Metadata = nil
+		}
 		out = append(out, a)
 	}
 	return out
@@ -107,6 +115,10 @@ func (s *ConfigSynthesizer) synthesizeClaudeKeys(ctx *SynthesisContext) []*corea
 			"source":  fmt.Sprintf("config:claude[%s]", token),
 			"api_key": key,
 		}
+		metadata := map[string]any{}
+		if ck.DisableCooling {
+			metadata["disable_cooling"] = true
+		}
 		if ck.Priority != 0 {
 			attrs["priority"] = strconv.Itoa(ck.Priority)
 		}
@@ -126,10 +138,14 @@ func (s *ConfigSynthesizer) synthesizeClaudeKeys(ctx *SynthesisContext) []*corea
 			Status:     coreauth.StatusActive,
 			ProxyURL:   proxyURL,
 			Attributes: attrs,
+			Metadata:   metadata,
 			CreatedAt:  now,
 			UpdatedAt:  now,
 		}
 		ApplyAuthExcludedModelsMeta(a, cfg, ck.ExcludedModels, "apikey")
+		if len(a.Metadata) == 0 {
+			a.Metadata = nil
+		}
 		out = append(out, a)
 	}
 	return out
@@ -154,6 +170,10 @@ func (s *ConfigSynthesizer) synthesizeCodexKeys(ctx *SynthesisContext) []*coreau
 			"source":  fmt.Sprintf("config:codex[%s]", token),
 			"api_key": key,
 		}
+		metadata := map[string]any{}
+		if ck.DisableCooling {
+			metadata["disable_cooling"] = true
+		}
 		if ck.Priority != 0 {
 			attrs["priority"] = strconv.Itoa(ck.Priority)
 		}
@@ -176,10 +196,14 @@ func (s *ConfigSynthesizer) synthesizeCodexKeys(ctx *SynthesisContext) []*coreau
 			Status:     coreauth.StatusActive,
 			ProxyURL:   proxyURL,
 			Attributes: attrs,
+			Metadata:   metadata,
 			CreatedAt:  now,
 			UpdatedAt:  now,
 		}
 		ApplyAuthExcludedModelsMeta(a, cfg, ck.ExcludedModels, "apikey")
+		if len(a.Metadata) == 0 {
+			a.Metadata = nil
+		}
 		out = append(out, a)
 	}
 	return out
@@ -203,6 +227,7 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 			providerName = "openai-compatibility"
 		}
 		base := strings.TrimSpace(compat.BaseURL)
+		disableCooling := compat.DisableCooling
 
 		// Handle new APIKeyEntries format (preferred)
 		createdEntries := 0
@@ -218,6 +243,10 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 				"compat_name":  compat.Name,
 				"provider_key": providerName,
 			}
+			metadata := map[string]any{}
+			if disableCooling {
+				metadata["disable_cooling"] = true
+			}
 			if compat.Priority != 0 {
 				attrs["priority"] = strconv.Itoa(compat.Priority)
 			}
@@ -236,9 +265,13 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 				Status:     coreauth.StatusActive,
 				ProxyURL:   proxyURL,
 				Attributes: attrs,
+				Metadata:   metadata,
 				CreatedAt:  now,
 				UpdatedAt:  now,
 			}
+			if len(a.Metadata) == 0 {
+				a.Metadata = nil
+			}
 			out = append(out, a)
 			createdEntries++
 		}
@@ -252,6 +285,10 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 				"compat_name":  compat.Name,
 				"provider_key": providerName,
 			}
+			metadata := map[string]any{}
+			if disableCooling {
+				metadata["disable_cooling"] = true
+			}
 			if compat.Priority != 0 {
 				attrs["priority"] = strconv.Itoa(compat.Priority)
 			}
@@ -266,9 +303,13 @@ func (s *ConfigSynthesizer) synthesizeOpenAICompat(ctx *SynthesisContext) []*cor
 				Prefix:     prefix,
 				Status:     coreauth.StatusActive,
 				Attributes: attrs,
+				Metadata:   metadata,
 				CreatedAt:  now,
 				UpdatedAt:  now,
 			}
+			if len(a.Metadata) == 0 {
+				a.Metadata = nil
+			}
 			out = append(out, a)
 		}
 	}