Add resilience: Spring Framework 7 @Retryable and @ConcurrencyLimit

Companion code for "Spring Framework 7's Built-in Resilience: @Retryable,
@ConcurrencyLimit, and What's Left for Resilience4j". Every retry counted
by recording real invocations: defaults, backoff and jitter, timeout,
reactive and CompletableFuture returns, the concurrency limit's BLOCK and
REJECT policies, retries around transactions, composition with
Resilience4j 2.4.0, and the annotation API across 7.0.0-7.0.9.

Co-Authored-By: Claude Opus 5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01C3TETMrqVUWeFkNtz3Jbo3

resilience/scripts/env.sh

@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+# Shared settings for every script in this module.
+MODULE_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+OUT="$MODULE_DIR/docs/output"
+JAR="$MODULE_DIR/target/resilience-1.0.0.jar"
+PORT="${PORT:-8081}"
+BASE="http://localhost:$PORT"
+PIDFILE="$MODULE_DIR/target/app.pid"
+LOG="$MODULE_DIR/target/app.log"
+mkdir -p "$OUT"