feat: add GitHub issue picker and API endpoints

Add GitHubIssuePickerDialog UI for selecting issues
Enable new session from GitHub issue from session sidebar
Implement GitHub issues/list/get/comments APIs across desktop, web, and VS Code

packages/ui/src/lib/api/types.ts

@@ -560,6 +560,54 @@ export type GitHubPullRequestMergeResult = {
   message?: string;
 };
 
+export type GitHubIssueLabel = {
+  name: string;
+  color?: string;
+};
+
+export type GitHubIssueSummary = {
+  number: number;
+  title: string;
+  url: string;
+  state: 'open' | 'closed';
+  author?: GitHubUserSummary | null;
+  labels?: GitHubIssueLabel[];
+};
+
+export type GitHubIssue = GitHubIssueSummary & {
+  body?: string;
+  assignees?: GitHubUserSummary[];
+  createdAt?: string;
+  updatedAt?: string;
+};
+
+export type GitHubIssueComment = {
+  id: number;
+  url: string;
+  body: string;
+  author?: GitHubUserSummary | null;
+  createdAt?: string;
+  updatedAt?: string;
+};
+
+export type GitHubIssuesListResult = {
+  connected: boolean;
+  repo?: GitHubRepoRef | null;
+  issues?: GitHubIssueSummary[];
+};
+
+export type GitHubIssueGetResult = {
+  connected: boolean;
+  repo?: GitHubRepoRef | null;
+  issue?: GitHubIssue | null;
+};
+
+export type GitHubIssueCommentsResult = {
+  connected: boolean;
+  repo?: GitHubRepoRef | null;
+  comments?: GitHubIssueComment[];
+};
+
 export type GitHubAuthStatus = {
   connected: boolean;
   user?: GitHubUserSummary | null;
@@ -591,6 +639,10 @@ export interface GitHubAPI {
   prCreate(payload: GitHubPullRequestCreateInput): Promise<GitHubPullRequest>;
   prMerge(payload: GitHubPullRequestMergeInput): Promise<GitHubPullRequestMergeResult>;
   prReady(payload: GitHubPullRequestReadyInput): Promise<GitHubPullRequestReadyResult>;
+
+  issuesList(directory: string): Promise<GitHubIssuesListResult>;
+  issueGet(directory: string, number: number): Promise<GitHubIssueGetResult>;
+  issueComments(directory: string, number: number): Promise<GitHubIssueCommentsResult>;
 }
 
 export interface RuntimeAPIs {

packages/ui/src/lib/opencode/client.ts

@@ -598,6 +598,7 @@ class OpencodeService {
     modelID: string;
     text: string;
     prefaceText?: string;
+    prefaceTextSynthetic?: boolean;
     agent?: string;
     variant?: string;
     files?: Array<{
@@ -609,6 +610,7 @@ class OpencodeService {
     /** Additional text/file parts to include (for batch sending queued messages) */
     additionalParts?: Array<{
       text: string;
+      synthetic?: boolean;
       files?: Array<{
         type: 'file';
         mime: string;
@@ -630,7 +632,8 @@ class OpencodeService {
     if (params.prefaceText && params.prefaceText.trim()) {
       parts.push({
         type: 'text',
-        text: params.prefaceText
+        text: params.prefaceText,
+        synthetic: params.prefaceTextSynthetic !== false,
       });
     }
 
@@ -663,7 +666,8 @@ class OpencodeService {
         if (additional.text && additional.text.trim()) {
           parts.push({
             type: 'text',
-            text: additional.text
+            text: additional.text,
+            ...(additional.synthetic ? { synthetic: true } : {}),
           });
         }
         if (additional.files && additional.files.length > 0) {