feat: add ci test runner, session routing, bash parser, and test fixtures

- script/run-ci-tests.ts: CI test sharding and isolation logic
- script/run-ci-tests.test.ts: tests for CI test target selection
- src/features/background-agent/session-route.ts: session prompt routing for background agents
- src/hooks/interactive-bash-session/parser.ts: interactive bash output parser
- src/hooks/ralph-loop/completion-promise-detector-test-input.ts: test fixture for completion promise detection

src/hooks/ralph-loop/completion-promise-detector-test-input.ts

@@ -0,0 +1,23 @@
+/// <reference types="bun-types" />
+import type { PluginInput } from "@opencode-ai/plugin"
+
+export type SessionMessage = {
+	info?: { role?: string }
+	parts?: Array<{ type: string; text?: string }>
+}
+
+export function createPluginInput(messages: SessionMessage[]): PluginInput {
+	const pluginInput = {
+		client: { session: {} } as PluginInput["client"],
+		project: {} as PluginInput["project"],
+		directory: "/tmp",
+		worktree: "/tmp",
+		serverUrl: new URL("http://localhost"),
+		$: {} as PluginInput["$"],
+	} as PluginInput
+
+	pluginInput.client.session.messages =
+		(async () => ({ data: messages })) as unknown as PluginInput["client"]["session"]["messages"]
+
+	return pluginInput
+}