Threadcore

First beta. Same engine as the alpha, three fixes and an honest version number.

• Fails readably when an out-of-date Threadcore API is on the classpath. If another mod bundles an older threadcore-api inside its own jar, that bundled copy can win over the standalone one even when the newer API is installed and the dependency is satisfied -- Fabric de-duplicates mods, not classes. The symptom was NoSuchMethodError: ThreadContext.isRecognisedMainThread() thrown during world construction, far from the cause and unreadable for a player. Threadcore now stops at preLaunch and names the mod responsible.
• Random ticks no longer run twice on regionized chunks. threadcore.regionRandomTicks is off by default and the startup banner reported it off, but the flag was only ever read by a test and a couple of diagnostics -- the call site in RegionExecutor ran the region random tick unconditionally. Vanilla's own chunk tick was not being suppressed either, so any chunk owned by a region that had entity work got random-ticked twice: crops and saplings grew, grass and fire spread, and ice and snow melted at roughly double the vanilla rate. If you ran the alpha, expect those to return to normal speed after updating -- that is this fix, not a slowdown. The flag is now honoured at the call site and inside the tick itself, and a test fails the build if the gate is ever removed again.
• The reported version is no longer wrong. The version lived in two places -- the build property that names the jar, and a literal in fabric.mod.json that is what Fabric and players actually see. They could diverge, and did. There is one source now.
• Still requires threadcore-api 0.0.2 or later, so an existing 0.0.2 install keeps working.