revert: restore full config overwrite + Common Config Snippet (revert 992dda5c)

Revert the partial key-field merging refactoring introduced in 992dda5c,
along with two dependent commits (24fa8a18, 87604b18) that referenced
the now-removed ClaudeQuickToggles component.

The whitelist-based partial merge approach had critical issues:
- Non-whitelisted custom fields were lost during provider switching
- Backfill permanently stripped non-key fields from the database
- Whitelist required constant maintenance to track upstream changes

This restores the proven "full config overwrite + Common Config Snippet"
architecture where each provider stores its complete configuration and
shared settings are managed via a separate snippet mechanism.

Reverted commits:
- 24fa8a18: context-aware JSON editor hint + hide quick toggles
- 87604b18: hide ClaudeQuickToggles when creating
- 992dda5c: partial key-field merging refactoring

Restored:
- Full config snapshot write (write_live_snapshot) for Claude/Codex/Gemini
- Full config backfill (settings_config = live_config)
- Common Config Snippet UI and backend commands
- 6 frontend components/hooks for common config editing
- configApi barrel export and DB snippet methods

Removed:
- ClaudeQuickToggles component
- write_live_partial / backfill_key_fields / patch_claude_live
- All KEY_FIELDS constants

src/components/providers/forms/ClaudeFormFields.tsx

@@ -10,11 +10,7 @@ import {
 } from "@/components/ui/select";
 import EndpointSpeedTest from "./EndpointSpeedTest";
 import { ApiKeySection, EndpointField } from "./shared";
-import type {
-  ProviderCategory,
-  ClaudeApiFormat,
-  ClaudeApiKeyField,
-} from "@/types";
+import type { ProviderCategory, ClaudeApiFormat } from "@/types";
 import type { TemplateValueConfig } from "@/config/claudeProviderPresets";
 
 interface EndpointCandidate {
@@ -72,10 +68,6 @@ interface ClaudeFormFieldsProps {
   // API Format (for third-party providers that use OpenAI Chat Completions format)
   apiFormat: ClaudeApiFormat;
   onApiFormatChange: (format: ClaudeApiFormat) => void;
-
-  // Auth Key Field (ANTHROPIC_AUTH_TOKEN vs ANTHROPIC_API_KEY)
-  apiKeyField: ClaudeApiKeyField;
-  onApiKeyFieldChange: (field: ClaudeApiKeyField) => void;
 }
 
 export function ClaudeFormFields({
@@ -110,8 +102,6 @@ export function ClaudeFormFields({
   speedTestEndpoints,
   apiFormat,
   onApiFormatChange,
-  apiKeyField,
-  onApiKeyFieldChange,
 }: ClaudeFormFieldsProps) {
   const { t } = useTranslation();
 
@@ -229,41 +219,6 @@ export function ClaudeFormFields({
         </div>
       )}
 
-      {/* 认证字段选择（仅非官方供应商显示） */}
-      {shouldShowModelSelector && (
-        <div className="space-y-2">
-          <FormLabel htmlFor="apiKeyField">
-            {t("providerForm.authField", { defaultValue: "认证字段" })}
-          </FormLabel>
-          <Select
-            value={apiKeyField}
-            onValueChange={(v) => onApiKeyFieldChange(v as ClaudeApiKeyField)}
-          >
-            <SelectTrigger id="apiKeyField" className="w-full">
-              <SelectValue />
-            </SelectTrigger>
-            <SelectContent>
-              <SelectItem value="ANTHROPIC_AUTH_TOKEN">
-                {t("providerForm.authFieldAuthToken", {
-                  defaultValue: "Auth Token (默认)",
-                })}
-              </SelectItem>
-              <SelectItem value="ANTHROPIC_API_KEY">
-                {t("providerForm.authFieldApiKey", {
-                  defaultValue: "API Key",
-                })}
-              </SelectItem>
-            </SelectContent>
-          </Select>
-          <p className="text-xs text-muted-foreground">
-            {t("providerForm.authFieldHint", {
-              defaultValue:
-                "大多数第三方供应商使用 Auth Token；少数供应商需要 API Key",
-            })}
-          </p>
-        </div>
-      )}
-
       {/* 模型选择器 */}
       {shouldShowModelSelector && (
         <div className="space-y-3">