feat(web): project detail views — missions, tasks, PRD viewer (#122)

- Add /projects/[id] page with tabbed layout: Overview, Tasks, Missions, PRD
- Project list page now navigates to detail page on click
- MissionTimeline component with status-ordered progression display
- TaskStatusSummary filter bar with per-status counts
- TaskDetailModal with full task info, tags, PR links, and notes
- PrdViewer renders markdown PRD content from project metadata
- Add Mission type to shared types.ts
- Wire all views to gateway REST API with loading/error states

Closes #122
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/web/src/components/projects/mission-timeline.tsx

@@ -0,0 +1,92 @@
+'use client';
+
+import { cn } from '@/lib/cn';
+import type { Mission, MissionStatus } from '@/lib/types';
+
+interface MissionTimelineProps {
+  missions: Mission[];
+}
+
+const statusOrder: MissionStatus[] = ['planning', 'active', 'paused', 'completed', 'failed'];
+
+const statusStyles: Record<MissionStatus, { dot: string; label: string; badge: string }> = {
+  planning: {
+    dot: 'bg-gray-400',
+    label: 'text-gray-400',
+    badge: 'bg-gray-600/20 text-gray-300',
+  },
+  active: {
+    dot: 'bg-blue-400',
+    label: 'text-blue-400',
+    badge: 'bg-blue-600/20 text-blue-400',
+  },
+  paused: {
+    dot: 'bg-warning',
+    label: 'text-warning',
+    badge: 'bg-warning/20 text-warning',
+  },
+  completed: {
+    dot: 'bg-success',
+    label: 'text-success',
+    badge: 'bg-success/20 text-success',
+  },
+  failed: {
+    dot: 'bg-error',
+    label: 'text-error',
+    badge: 'bg-error/20 text-error',
+  },
+};
+
+function sortMissions(missions: Mission[]): Mission[] {
+  return [...missions].sort((a, b) => {
+    const aIdx = statusOrder.indexOf(a.status);
+    const bIdx = statusOrder.indexOf(b.status);
+    if (aIdx !== bIdx) return aIdx - bIdx;
+    return new Date(a.createdAt).getTime() - new Date(b.createdAt).getTime();
+  });
+}
+
+export function MissionTimeline({ missions }: MissionTimelineProps): React.ReactElement {
+  if (missions.length === 0) {
+    return (
+      <div className="py-6 text-center">
+        <p className="text-sm text-text-muted">No missions for this project</p>
+      </div>
+    );
+  }
+
+  const sorted = sortMissions(missions);
+
+  return (
+    <ol className="relative space-y-0">
+      {sorted.map((mission, idx) => {
+        const styles = statusStyles[mission.status] ?? statusStyles.planning;
+        const isLast = idx === sorted.length - 1;
+        return (
+          <li key={mission.id} className="relative flex gap-4 pb-6 last:pb-0">
+            {/* Vertical line */}
+            {!isLast && <div className="absolute left-2.5 top-5 h-full w-px bg-surface-border" />}
+            {/* Status dot */}
+            <div
+              className={cn('mt-1 h-5 w-5 shrink-0 rounded-full border-2 border-bg', styles.dot)}
+            />
+            <div className="flex-1 rounded-lg border border-surface-border bg-surface-card p-3">
+              <div className="flex items-start justify-between gap-2">
+                <span className="text-sm font-medium text-text-primary">{mission.name}</span>
+                <span className={cn('shrink-0 rounded-full px-2 py-0.5 text-xs', styles.badge)}>
+                  {mission.status}
+                </span>
+              </div>
+              {mission.description && (
+                <p className="mt-1 text-xs text-text-muted">{mission.description}</p>
+              )}
+              <p className="mt-2 text-xs text-text-muted">
+                Created {new Date(mission.createdAt).toLocaleDateString()}
+              </p>
+            </div>
+          </li>
+        );
+      })}
+    </ol>
+  );
+}