Competition/Round architecture: full platform rewrite (Phases 1-9)

Replace Pipeline/Stage system with Competition/Round architecture.
New schema: Competition, Round (7 types), JuryGroup, AssignmentPolicy,
ProjectRoundState, DeliberationSession, ResultLock, SubmissionWindow.
New services: round-engine, round-assignment, deliberation, result-lock,
submission-manager, competition-context, ai-prompt-guard.
Full admin/jury/applicant/mentor UI rewrite. AI prompt hardening with
structured prompts, retry logic, and injection detection. All legacy
pipeline/stage code removed. 4 new migrations + seed aligned.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/lib/feature-flags.ts

@@ -0,0 +1,49 @@
+import { prisma } from '@/lib/prisma'
+
+/**
+ * Feature flag keys — used to control progressive rollout of new architecture.
+ * Stored as SystemSetting records with category FEATURE_FLAGS.
+ */
+export const FEATURE_FLAGS = {
+  /** Use Competition/Round model instead of Pipeline/Track/Stage */
+  USE_COMPETITION_MODEL: 'feature.useCompetitionModel',
+} as const
+
+type FeatureFlagKey = (typeof FEATURE_FLAGS)[keyof typeof FEATURE_FLAGS]
+
+/**
+ * Check if a feature flag is enabled (server-side).
+ * Returns false if the flag doesn't exist in the database.
+ */
+export async function isFeatureEnabled(flag: FeatureFlagKey): Promise<boolean> {
+  try {
+    const setting = await prisma.systemSettings.findUnique({
+      where: { key: flag },
+    })
+    // Default to true for competition model (legacy Pipeline system removed)
+    if (!setting) return flag === FEATURE_FLAGS.USE_COMPETITION_MODEL ? true : false
+    return setting.value === 'true'
+  } catch {
+    return flag === FEATURE_FLAGS.USE_COMPETITION_MODEL ? true : false
+  }
+}
+
+/**
+ * Set a feature flag value (server-side, admin only).
+ */
+export async function setFeatureFlag(
+  flag: FeatureFlagKey,
+  enabled: boolean,
+): Promise<void> {
+  await prisma.systemSettings.upsert({
+    where: { key: flag },
+    update: { value: String(enabled) },
+    create: {
+      key: flag,
+      value: String(enabled),
+      type: 'BOOLEAN',
+      category: 'FEATURE_FLAGS',
+      description: `Feature flag: ${flag}`,
+    },
+  })
+}