✨ feat(vscode): 设置面板可配头脑风暴/实施/测试会话的默认 profile

三类会话的 profile 此前只有工单级字段，留空就硬编码落到 official，
想整体换模型只能一个工单一个工单改。

设置面板新增三个下拉，与冲突解决/提交/改动说明的 profile 选择同区。
解析链路变成：工单级字段 > 对应的全局默认设置 > getDefaultProfilePath()，
三类之间仍互不回退。新建工单的头脑风暴会话也走同一条链路。

Claude-Session: https://claude.ai/code/session_01REdhpbaNyqWASF2HWsnTFv

vscode/webview-ui/src/hooks/useIssues.ts

@@ -55,6 +55,9 @@ export interface SettingsValues {
   implTabPreCreateScript: string
   implTabPostCloseScript: string
   splitNewTerminals: boolean
+  defaultBrainstormProfilePath: string
+  defaultImplementProfilePath: string
+  defaultTestProfilePath: string
   conflictResolutionProfilePath: string
   commitProfilePath: string
   prDiffSummaryProfilePath: string
@@ -91,6 +94,9 @@ export interface SettingsOverlayState {
   implTabPreCreateScript: string
   implTabPostCloseScript: string
   splitNewTerminals: boolean
+  defaultBrainstormProfilePath: string
+  defaultImplementProfilePath: string
+  defaultTestProfilePath: string
   conflictResolutionProfilePath: string
   commitProfilePath: string
   prDiffSummaryProfilePath: string
@@ -422,6 +428,9 @@ export function useIssues(): UseIssuesResult {
       implTabPreCreateScript: values.implTabPreCreateScript,
       implTabPostCloseScript: values.implTabPostCloseScript,
       splitNewTerminals: values.splitNewTerminals,
+      defaultBrainstormProfilePath: values.defaultBrainstormProfilePath,
+      defaultImplementProfilePath: values.defaultImplementProfilePath,
+      defaultTestProfilePath: values.defaultTestProfilePath,
       conflictResolutionProfilePath: values.conflictResolutionProfilePath,
       commitProfilePath: values.commitProfilePath,
       prDiffSummaryProfilePath: values.prDiffSummaryProfilePath,
@@ -824,6 +833,9 @@ export function useIssues(): UseIssuesResult {
             implTabPreCreateScript: msg.implTabPreCreateScript,
             implTabPostCloseScript: msg.implTabPostCloseScript,
             splitNewTerminals: msg.splitNewTerminals,
+            defaultBrainstormProfilePath: msg.defaultBrainstormProfilePath,
+            defaultImplementProfilePath: msg.defaultImplementProfilePath,
+            defaultTestProfilePath: msg.defaultTestProfilePath,
             conflictResolutionProfilePath: msg.conflictResolutionProfilePath,
             commitProfilePath: msg.commitProfilePath,
             prDiffSummaryProfilePath: msg.prDiffSummaryProfilePath,