refactor(Core): decompose constructCore() into focused init methods

- Extracted Core#constructCore into: initDirectories(), ensureDir(String),
  initOllamaUrl(), initLogWriter(), rotateLogFile(), initScheduler(),
  initShutdownHook(), closeLogWriter(), saveMessages(),
  buildMessagesArray(), writeMessagesTo(File, JSONArray)
- Overloaded constructors for Core
- Cleaned up some Javadocs

Fixed error(AddArrayMemory)
- Line 51 used the wrong value

Updated minor version for(::Core)

Dev note: Long overdue — that generic init block was ugly and is finally
laid to rest.

Core/build.gradle

@@ -3,7 +3,7 @@ plugins {
 }
 
 group = 'me.zacharias.neurodock'
-version = '1.5'
+version = '1.6'
 
 dependencies {
     implementation project(":Plugin-API")