Add missing Javadoc comments to resolve build warnings

[Copilot]

Running mvn clean package -Peverything -ntp produces 52 Javadoc warnings for undocumented public methods. This adds the required documentation to eliminate all warnings.

Changes

• locker/Lock.java — Document 10 public methods (constructor, copy, toMap, state setters, predicates)
• locker-tests/AbstractLockServiceTest.java — Document abstract method and 25 test methods
• api module — Document Spring beans and exception handlers across App, EpochTimeProviderConfiguration, UuidGeneratorConfiguration, GlobalExceptionHandler, MyCustomSecurityConfiguration
• locker-memory, locker-firestore, locker-etcd, locker-dynamodb — Document @Bean factory methods in config classes

Example

/**
 * Checks if the lock has expired.
 *
 * @param now the current time in epoch seconds
 * @return true if the lock has expired, false otherwise
 */
public boolean isExpired(long now) {
    return this.expiry != null && this.expiry < now;
}

Also removes trailing whitespace across touched files.

Original prompt

When I run "mvn clean package -Peverything -ntp" there are warnings about missing documentation. Can you go about adding the missing Javadocs that are being called out for warnings for this application. I don't want unnecessary Javadocs, just those being called out so that all of these warnings are resolved.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 38.75%. Comparing base (2a615f9) to head (67a236d).
⚠️ Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
...cecentral/locker/dynamodb/DynamoDbLockService.java	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##               main     #103   +/-   ##
=========================================
  Coverage     38.75%   38.75%           
  Complexity      136      136           
=========================================
  Files            31       31           
  Lines          1027     1027           
  Branches        112      112           
=========================================
  Hits            398      398           
  Misses          600      600           
  Partials         29       29           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.