Fix crafting, ranged combat and old-world upgrades in 1.13

[SkyBlade1978]

This brings the accepted 1.12 fixes into the native Minecraft 1.13.2 port. The fixes use Base Metals' own code; this branch still has no MMDLib dependency.

What changed

• #473: metal nuggets and powders no longer fuel furnaces. Coal and charcoal keep their fuel values.
• #474: Diamond, Emerald, Gold and Quartz doors use six ingredients, so their recipes do not collide with trapdoors.
• #467: steel rail recipes produce 16 rails. Bows and crossbows combine their material's damage with the ammunition material before adding Power.
• Plate repairs require a damaged matching item and a plate, reject extra ingredients, and keep names, enchantments and other saved data. They stay out of the recipe book.
• Crafting recipes unlock from the right ingredients, including tags. Different tools and weapons no longer share one recipe-book cell.
• Obsidian conversion and Vanilla Bits sword/bolt recipes no longer return more material through recycling than they cost.
• Old chunks containing Base Metals only in inventories are protected during world conversion, not just chunks with Base Metals blocks.
• Pin the published OreSpawn 4.1.0.113021 file and checksum instead of the local candidate. The eleven ore rules and runtime compatibility range are unchanged.
• Refresh the README and changelog, strengthen the ignore rules, and keep the new upgrade comparison helper in the test probe rather than the released mod.

Checks completed locally

• All 39 unit tests, generated-data checks, release auditing and Eclipse isolation passed.
• The packaged client created, rendered and saved a world. The dedicated server passed fresh and reload probes with 16,859 assertions.
• A disposable 1.12 upgrade verified 20,553 block states, 1,038 item stacks, 96 armour pieces, 33 buckets and nine player items with no mismatches. The original fixture's hashes stayed unchanged.
• Two clean builds produced byte-identical main, sources and Javadoc jars.
• The commit contains no agent files, worlds, logs or generated test reports. Permanent tests, reference data and generated game resources remain included.

This PR does not publish a release or add the 1.12 content-mode feature to 1.13.