Replace session picker modal with instance welcome view

Transform the session picker from a modal into a comprehensive welcome screen that displays instance metadata, session history, and creation options. The new view provides full keyboard navigation, shows MCP server status, OpenCode binary path, and project information in a compact, space-efficient layout.

Key features:
- Instance metadata sidebar showing folder, project, VCS, version, binary path, MCP status, and server info
- Session list with keyboard navigation (↑↓, PgUp/PgDn, Home/End, Enter)
- Cmd+Enter shortcut to create new session from anywhere
- Compact design with efficient space usage
- Visual MCP server status indicators (running/stopped/error)
- Scrollable layout that keeps "New Session" section accessible

electron/main/ipc.ts

@@ -35,13 +35,13 @@ export function setupInstanceIPC(mainWindow: BrowserWindow) {
     instances.set(id, instance)
 
     try {
-      const { pid, port } = await processManager.spawn(folder, id)
+      const { pid, port, binaryPath } = await processManager.spawn(folder, id)
 
       instance.port = port
       instance.pid = pid
       instance.status = "ready"
 
-      mainWindow.webContents.send("instance:started", { id, port, pid })
+      mainWindow.webContents.send("instance:started", { id, port, pid, binaryPath })
 
       const meta = processManager.getAllProcesses().get(pid)
       if (meta) {
@@ -51,7 +51,7 @@ export function setupInstanceIPC(mainWindow: BrowserWindow) {
         })
       }
 
-      return { id, port, pid }
+      return { id, port, pid, binaryPath }
     } catch (error) {
       instance.status = "error"
       instance.error = error instanceof Error ? error.message : String(error)

electron/main/process-manager.ts

@@ -6,6 +6,7 @@ import { execSync } from "child_process"
 export interface ProcessInfo {
   pid: number
   port: number
+  binaryPath: string
 }
 
 interface ProcessMeta {
@@ -51,7 +52,7 @@ class ProcessManager {
 
   async spawn(folder: string, instanceId: string): Promise<ProcessInfo> {
     this.validateFolder(folder)
-    this.validateOpenCodeBinary()
+    const binaryPath = this.validateOpenCodeBinary()
 
     this.sendLog(instanceId, "info", `Starting OpenCode server for ${folder}...`)
 
@@ -102,7 +103,7 @@ class ProcessManager {
             }
 
             this.processes.set(child.pid!, meta)
-            resolve({ pid: child.pid!, port })
+            resolve({ pid: child.pid!, port, binaryPath })
           }
 
           const meta = this.processes.get(child.pid!)
@@ -208,10 +209,12 @@ class ProcessManager {
     }
   }
 
-  private validateOpenCodeBinary(): void {
+  private validateOpenCodeBinary(): string {
     const command = process.platform === "win32" ? "where opencode" : "which opencode"
     try {
-      execSync(command, { stdio: "pipe" })
+      const output = execSync(command, { stdio: "pipe", encoding: "utf-8" })
+      const paths = output.trim().split("\n")
+      return paths[0].trim()
     } catch {
       throw new Error(
         "opencode binary not found in PATH. Please install OpenCode CLI first: npm install -g @opencode/cli",

electron/preload/index.ts

@@ -2,9 +2,9 @@ import { contextBridge, ipcRenderer } from "electron"
 
 export interface ElectronAPI {
   selectFolder: () => Promise<string | null>
-  createInstance: (id: string, folder: string) => Promise<{ id: string; port: number; pid: number }>
+  createInstance: (id: string, folder: string) => Promise<{ id: string; port: number; pid: number; binaryPath: string }>
   stopInstance: (pid: number) => Promise<void>
-  onInstanceStarted: (callback: (data: { id: string; port: number; pid: number }) => void) => void
+  onInstanceStarted: (callback: (data: { id: string; port: number; pid: number; binaryPath: string }) => void) => void
   onInstanceError: (callback: (data: { id: string; error: string }) => void) => void
   onInstanceStopped: (callback: (data: { id: string }) => void) => void
   onInstanceLog: (