feat(FN-971): add mission status summary with progress bar to mission list

- Add MissionSummary type and getMissionSummary method to MissionStore
- Include mission summary data in GET /missions API endpoint
- Update frontend types and API client for mission summary
- Display mission status summary with progress bar on MissionManager list cards
- Add CSS styles for progress bar and summary display
- Update MissionManager tests for summary display

packages/core/src/index.ts

@@ -110,7 +110,7 @@ export type {
   FeatureLinkedPayload,
 } from "./mission-types.js";
 export { MissionStore } from "./mission-store.js";
-export type { MissionStoreEvents } from "./mission-store.js";
+export type { MissionStoreEvents, MissionSummary } from "./mission-store.js";
 
 // ── Central Infrastructure (Multi-Project Support) ───────────────────────────
 

packages/core/src/mission-store.ts

@@ -31,6 +31,22 @@ import type {
   InterviewState,
 } from "./mission-types.js";
 
+// ── Mission Summary Type ─────────────────────────────────────────────
+
+/** Status summary for a mission, computed from its hierarchy. */
+export interface MissionSummary {
+  /** Total number of milestones in the mission */
+  totalMilestones: number;
+  /** Number of milestones with status "complete" */
+  completedMilestones: number;
+  /** Total number of features across all slices */
+  totalFeatures: number;
+  /** Number of features with status "done" */
+  completedFeatures: number;
+  /** Computed progress percentage (0–100), based on features or milestones */
+  progressPercent: number;
+}
+
 // ── Event Types ─────────────────────────────────────────────────────
 
 export interface MissionStoreEvents {
@@ -247,6 +263,51 @@ export class MissionStore extends EventEmitter<MissionStoreEvents> {
     return (rows as any[]).map((row) => this.rowToMission(row));
   }
 
+  /**
+   * Get a status summary for a mission, computing milestone and feature counts
+   * and progress percentage from the hierarchy.
+   *
+   * Progress is calculated as:
+   * - (completedFeatures / totalFeatures) * 100 if there are features
+   * - (completedMilestones / totalMilestones) * 100 if there are milestones but no features
+   * - 0 otherwise
+   *
+   * @param missionId - Mission ID
+   * @returns MissionSummary with counts and progress
+   */
+  getMissionSummary(missionId: string): MissionSummary {
+    const milestones = this.listMilestones(missionId);
+    const totalMilestones = milestones.length;
+    const completedMilestones = milestones.filter((m) => m.status === "complete").length;
+
+    let totalFeatures = 0;
+    let completedFeatures = 0;
+
+    for (const milestone of milestones) {
+      const slices = this.listSlices(milestone.id);
+      for (const slice of slices) {
+        const features = this.listFeatures(slice.id);
+        totalFeatures += features.length;
+        completedFeatures += features.filter((f) => f.status === "done").length;
+      }
+    }
+
+    let progressPercent = 0;
+    if (totalFeatures > 0) {
+      progressPercent = Math.round((completedFeatures / totalFeatures) * 100);
+    } else if (totalMilestones > 0) {
+      progressPercent = Math.round((completedMilestones / totalMilestones) * 100);
+    }
+
+    return {
+      totalMilestones,
+      completedMilestones,
+      totalFeatures,
+      completedFeatures,
+      progressPercent,
+    };
+  }
+
   /**
    * Update a mission.
    *