feat: add main features

Agents for developpement added + frontend add + backend added. Git viewer created + agent and template creator + layout and project creator

frontend/src/features/agents/index.ts

@@ -0,0 +1,8 @@
+/**
+ * Agents feature — public surface (L6).
+ */
+
+export { AgentsPanel } from "./AgentsPanel";
+export type { AgentsPanelProps } from "./AgentsPanel";
+export { useAgents } from "./useAgents";
+export type { AgentsViewModel } from "./useAgents";