Implement get_all_milestones view function

campaign/src/get_all_milestones.rs

@@ -0,0 +1,19 @@
+use soroban_sdk::{Env, Vec};
+use crate::types::MilestoneData;
+use crate::storage::{get_campaign, get_milestone};
+
+/// Issue #200 – `get_all_milestones` view function
+///
+/// Returns all milestones in index order.
+/// No authentication required.
+/// Handles campaigns with 1–5 milestones.
+pub fn get_all_milestones(env: &Env) -> Vec<MilestoneData> {
+    let campaign = get_campaign(env).expect("campaign not initialized");
+    let mut milestones = Vec::new(env);
+    for i in 0..campaign.milestone_count {
+        if let Some(m) = get_milestone(env, i) {
+            milestones.push_back(m);
+        }
+    }
+    milestones
+}