wire home ai chat

frontend/src/lib/components/home/HomeAIChat.svelte

@@ -1,13 +1,32 @@
 <script lang="ts">
 	import TextInput from '$lib/components/text_input/TextInput.svelte'
-	import { ArrowRight, PlusIcon, Sparkles } from 'lucide-svelte'
+	import { ArrowRight } from 'lucide-svelte'
 	import Button from '../common/button/Button.svelte'
 	import ProviderModelSelector from '../copilot/chat/ProviderModelSelector.svelte'
+	import { startSessionWithPrompt } from '../sessions/sessionSwitch.svelte'
 
-	// UI only for now — no submit wiring yet.
 	let value = $state('')
 	let placeholder = $state('')
 
+	let starting = $state(false)
+	async function start() {
+		if (starting || !value.trim()) return
+		starting = true
+		try {
+			await startSessionWithPrompt(value)
+		} finally {
+			starting = false
+		}
+	}
+
+	// Enter starts the session; Shift+Enter keeps inserting a newline.
+	function onKeydown(e: KeyboardEvent) {
+		if (e.key === 'Enter' && !e.shiftKey) {
+			e.preventDefault()
+			start()
+		}
+	}
+
 	const prompts = [
 		'Sync new Salesforce leads into a postgres table every hour',
 		'Build a workflow that triggers on a Discord message, checks for offensive language using an LLM, and possibly block them'
@@ -60,13 +79,15 @@
 			bind:value
 			class="resize-none px-4 py-3 pb-9 shadow-lg"
 			underlyingInputEl="textarea"
-			inputProps={{ rows: 4, placeholder }}
+			inputProps={{ rows: 4, placeholder, onkeydown: onKeydown }}
 		/>
 		<Button
 			endIcon={{ icon: ArrowRight }}
 			wrapperClasses="absolute right-2 bottom-3.5"
-			variant="default"
+			variant={value.trim() ? 'accent' : 'default'}
 			iconOnly
+			disabled={!value.trim() || starting}
+			onclick={start}
 		></Button>
 		<div
 			class="absolute left-3 bottom-4 flex items-center border rounded-md bg-surface-tertiary px-1"

frontend/src/lib/components/sessions/sessionSwitch.svelte.ts

@@ -3,6 +3,7 @@ import { goto } from '$lib/navigation'
 import { workspaceStore } from '$lib/stores'
 import {
 	createSession,
+	queueTransientDraftPrompt,
 	selectSession,
 	sessionInCurrentFamily,
 	sessionState,
@@ -49,6 +50,19 @@ export async function enterSessionMode(opts?: { replace?: boolean }): Promise<vo
 	})
 }
 
+// Start a fresh AI session seeded with a prompt composed elsewhere (e.g. the
+// home page composer), then route into session mode. The prompt is queued onto
+// the transient draft so the session's chat input restores it on mount — the
+// same path a reload uses — leaving it composed-but-unsent for the user to
+// review and send. No-op routing is fine for a blank prompt; callers guard.
+export async function startSessionWithPrompt(prompt: string): Promise<void> {
+	const session = createSession()
+	const text = prompt.trim()
+	if (text) queueTransientDraftPrompt(session.id, text)
+	selectSession(session.id)
+	await goto(`/sessions?session_name=${encodeURIComponent(session.name)}`)
+}
+
 // Exit session mode: back to the last navigation route (home as a fallback).
 export async function exitSessionMode(): Promise<void> {
 	let target = lastNavRoute || '/'