Fix IndexOutOfBoundsException in GitUtil.getRepositoryURL when no remotes configured

[Copilot]

Recording fails with IndexOutOfBoundsException in GitUtil.getRepositoryURL when the git repository has no remotes — the fallback path of remotes.get(0) is hit unconditionally on a potentially empty list.

Changes

• Guard against empty remotes list — return null early if remotes.isEmpty() instead of falling through to remotes.get(0)
• Guard against empty URIs list — return null if the selected remote has no URIs configured
• Use orElseGet over orElse — avoids eagerly evaluating remotes.get(0) when "origin" is present
• getRepositoryURL() returns null instead of "" when no URL is available, allowing callers to distinguish "no remote" from an actual empty string
• AppMapSerializer.writeMetadata() only writes the repository key when getRepositoryURL() returns a non-null value

// Before
List<URIish> uris = originConfig.isPresent() ? originConfig.get().getURIs() : remotes.get(0).getURIs();
return uris.get(0).toASCIIString(); // throws if remotes or uris is empty

// After
if (remotes.isEmpty()) return null;
RemoteConfig remote = originConfig.orElseGet(() -> remotes.get(0));
List<URIish> uris = remote.getURIs();
if (uris.isEmpty()) return null;
return uris.get(0).toASCIIString();

[kgilpin]

getRepositoryURL should be modified to return String | null, or to return String[] which might be empty, and caller sites updated accordingly. @copilot

[Copilot]

getRepositoryURL should be modified to return String | null, or to return String[] which might be empty, and caller sites updated accordingly. @copilot

Done in 5956839. getRepositoryURL() now returns null (instead of "") when no remotes are configured, a remote has no URIs, or an exception occurs. The caller in AppMapSerializer.writeMetadata() now only writes the repository key when the returned value is non-null.