feat(webapp): add compute migration env config

Author: nicktrn

apps/webapp/app/env.server.ts

@@ -158,6 +158,16 @@ const EnvironmentSchema = z
     WORKER_SCHEMA: z.string().default("graphile_worker"),
     WORKER_CONCURRENCY: z.coerce.number().int().default(10),
     WORKER_POLL_INTERVAL: z.coerce.number().int().default(1000),
+    // JSON map of container-region masterQueue -> compute-backing masterQueue.
+    // Absence of an entry means that region is never migrated (e.g. EU until it
+    // has a compute backing). Example: {"us-east-1":"us-east-1-next"}
+    COMPUTE_BACKING_MAP: z.string().default("{}"),
+    // How often each replica reloads the global flags snapshot from the DB.
+    // Sets kill/ramp propagation latency.
+    GLOBAL_FLAGS_RELOAD_INTERVAL_MS: z.coerce.number().int().default(5000),
+    // Max time the first trigger blocks waiting for the initial flags load
+    // before falling back to defaults (off = container, the safe direction).
+    GLOBAL_FLAGS_READY_TIMEOUT_MS: z.coerce.number().int().default(5000),
     WORKER_ENABLED: z.string().default("true"),
     GRACEFUL_SHUTDOWN_TIMEOUT: z.coerce.number().int().default(60000),
     DISABLE_SSE: z.string().optional(),