feat(v26.8-Alpha.5): DEC-PRE261 Option A foundation - Mojang official mappings cross-resolution

- OfficialMappings: parses Mojang client.txt ProGuard format (class lines;
  members/comments skipped) into an official->runtime reverse index.
- GameContentBindingInstaller: setOfficialMappings() + rt() translation -
  binder class targets (BuiltInRegistries, Registry, Identifier, Item,
  Block) resolve through the chain on REMAPPED profiles when mappings are
  supplied. Without mappings the PROFILE_UNSUPPORTED gate stands.
- Scope note: class-level chain proven; member-level (field/method)
  translation is the next increment - client.txt member lines need
  per-class keyed parsing.
- 4 unit tests (parse/skip rules, pass-through, absent-file, remap gate).
- Version bumped to v26.8-Alpha.5.

Author: StarsailsClover

aprism-loader-core/src/main/java/com/aprism/loader/contentbind/GameContentBindingInstaller.java

@@ -46,6 +46,7 @@ public final class GameContentBindingInstaller {
 
     private final GameRegistries gameRegistries;
     private boolean remapProfile;
+    private OfficialMappings officialMappings;
 
     /**
      * Outcome of one bind attempt.
@@ -73,6 +74,22 @@ public void setRemapProfile(boolean remapProfile) {
         this.remapProfile = remapProfile;
     }
 
+    /**
+     * Supplies Mojang official mappings (client.txt) enabling cross-mapped
+     * binding on REMAPPED profiles (DEC-PRE261 Option A, v26.8-Alpha.5).
+     */
+    public void setOfficialMappings(OfficialMappings mappings) {
+        this.officialMappings = mappings;
+    }
+
+    /** Translates an official target name to the runtime name when needed. */
+    private String rt(String officialName) {
+        if (remapProfile && officialMappings != null) {
+            return officialMappings.runtimeName(officialName);
+        }
+        return officialName;
+    }
+
     /**
      * Binds every registered item and block into the real registries.
      * Never throws; failures are isolated per entry.
@@ -210,16 +227,16 @@ private RegistryHandles resolveHandles() {
             ClassLoader loader = Thread.currentThread().getContextClassLoader() != null
                     ? Thread.currentThread().getContextClassLoader()
                     : getClass().getClassLoader();
-            Class<?> registries = loader.loadClass(BUILT_IN_REGISTRIES);
+            Class<?> registries = loader.loadClass(rt(BUILT_IN_REGISTRIES));
             Class<?> registryHelper = loader.loadClass(REGISTRY_HELPER);
-            Class<?> registryIface = loader.loadClass("net.minecraft.core.Registry");
-            Class<?> identifier = loader.loadClass(IDENTIFIER);
+            Class<?> registryIface = loader.loadClass(rt("net.minecraft.core.Registry"));
+            Class<?> identifier = loader.loadClass(rt(IDENTIFIER));
             Field itemField = registries.getField("ITEM");
             Field blockField = registries.getField("BLOCK");
             Object itemRegistry = itemField.get(null);
             Object blockRegistry = blockField.get(null);
-            Class<?> itemClass = loader.loadClass(MC_ITEM);
-            Class<?> blockClass = loader.loadClass(MC_BLOCK);
+            Class<?> itemClass = loader.loadClass(rt(MC_ITEM));
+            Class<?> blockClass = loader.loadClass(rt(MC_BLOCK));
             return new RegistryHandles(registryIface, registryHelper, itemRegistry,
                     blockRegistry, itemClass, blockClass,
                     IdentifierFactory.detect(identifier));

aprism-loader-core/src/main/java/com/aprism/loader/contentbind/OfficialMappings.java

@@ -0,0 +1,94 @@
+package com.aprism.loader.contentbind;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.logging.Logger;
+// GitHub@NDBlockConnect | BlockConnect@StarsailsClover
+
+/**
+ * Loads Mojang's official {@code client.txt} ProGuard mapping and resolves
+ * official Mojang class names to their runtime (obfuscated) names
+ * (v26.8-Alpha.5, DEC-PRE261 Option A foundation).
+ *
+ * <p>On the REMAPPED profile the runtime classes carry obfuscated names.
+ * Binding targets written against official names must therefore be
+ * translated: {@code official --[client.txt reverse]--> obfuscated
+ * (runtime)}. Member mappings are skipped; classes suffice for binder
+ * targets.
+ *
+ * <p>File format (ProGuard): class lines are
+ * {@code obf.qual.Name -> official.qual.Name:}; member lines are indented.
+ *
+ * @author BlockConnect@StarsailsClover
+ */
+public final class OfficialMappings {
+// GitHub@NDBlockConnect | BlockConnect@StarsailsClover
+
+    private static final Logger LOG = Logger.getLogger("aprism.contentbind");
+
+    private final Map<String, String> officialToRuntime;
+
+    private OfficialMappings(Map<String, String> officialToRuntime) {
+        this.officialToRuntime = officialToRuntime;
+    }
+
+    /**
+     * Parses a Mojang {@code client.txt} mapping file.
+     *
+     * @param clientTxt path to the mapping file
+     * @return the loaded mapping, or null when the file is absent
+     * @throws IOException when the file exists but cannot be read
+     */
+    public static OfficialMappings load(Path clientTxt) throws IOException {
+        if (clientTxt == null || !Files.isRegularFile(clientTxt)) {
+            return null;
+        }
+        Map<String, String> map = new HashMap<>(30_000);
+        try (BufferedReader br = Files.newBufferedReader(clientTxt,
+                StandardCharsets.UTF_8)) {
+            String line;
+            while ((line = br.readLine()) != null) {
+                if (line.isEmpty() || line.startsWith(" ") || line.startsWith("#")) {
+                    continue; // members/comments skipped; classes only
+                }
+                int arrow = line.indexOf(" -> ");
+                if (arrow < 0) {
+                    continue;
+                }
+                String officialPart = line.substring(arrow + 4);
+                if (officialPart.endsWith(":")) {
+                    officialPart = officialPart.substring(0,
+                            officialPart.length() - 1);
+                }
+                // Keep the LAST occurrence (inner-class lines may repeat).
+                map.put(officialPart, line.substring(0, arrow));
+            }
+        }
+        int size = map.size();
+        LOG.info("OfficialMappings loaded: " + size + " class entries");
+        return new OfficialMappings(map);
+    }
+
+    /**
+     * Resolves an official Mojang class name to its runtime name.
+     *
+     * @param officialName e.g. {@code net.minecraft.core.registries.BuiltInRegistries}
+     * @return the runtime (obfuscated) name, or the input unchanged when the
+     *         name is not in the mapping (e.g. already-runtime or library)
+     */
+    public String runtimeName(String officialName) {
+        return officialToRuntime.getOrDefault(officialName, officialName);
+    }
+
+    /**
+     * @return the number of mapped classes
+     */
+    public int size() {
+        return officialToRuntime.size();
+    }
+}

aprism-loader-core/src/test/java/com/aprism/loader/contentbind/OfficialMappingsTest.java

@@ -0,0 +1,72 @@
+package com.aprism.loader.contentbind;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+// GitHub@NDBlockConnect | BlockConnect@StarsailsClover
+
+/**
+ * Tests for {@link OfficialMappings}: ProGuard client.txt parsing and
+ * official-to-runtime class-name resolution (DEC-PRE261 Option A
+ * foundation).
+ */
+class OfficialMappingsTest {
+
+    @TempDir
+    Path tempDir;
+
+    private static final String CLIENT_TXT = """
+            # comment line should be skipped
+            abc.def -> net.minecraft.core.registries.BuiltInRegistries:
+              field a -> ITEM
+            ghi -> net.minecraft.world.item.Item:
+              method a(net.minecraft.world.item.ItemStack) -> method_1
+            skip.Me -> skip.Me:
+            """;
+
+    @Test
+    void loadsClassEntriesAndSkipsMembersAndComments() throws Exception {
+        Path f = tempDir.resolve("client.txt");
+        Files.writeString(f, CLIENT_TXT);
+        OfficialMappings m = OfficialMappings.load(f);
+
+        assertNotNull(m);
+        assertTrue(m.size() >= 3);
+        assertEquals("abc.def",
+                m.runtimeName("net.minecraft.core.registries.BuiltInRegistries"));
+        assertEquals("ghi", m.runtimeName("net.minecraft.world.item.Item"));
+    }
+
+    @Test
+    void unknownNamesPassThroughUnchanged() throws Exception {
+        Path f = tempDir.resolve("client.txt");
+        Files.writeString(f, CLIENT_TXT);
+        OfficialMappings m = OfficialMappings.load(f);
+
+        assertEquals("com.mojang.brigadier.CommandDispatcher",
+                m.runtimeName("com.mojang.brigadier.CommandDispatcher"));
+    }
+
+    @Test
+    void absentFileLoadsAsNull() throws Exception {
+        assertNull(OfficialMappings.load(tempDir.resolve("nope.txt")));
+        assertNull(OfficialMappings.load(null));
+    }
+
+    @Test
+    void remapGateStillRefusesWithoutMappings() {
+        // Without official mappings, REMAPPED profiles keep refusing.
+        var reg = new com.aprism.loader.registry.GameRegistries();
+        var k = com.aprism.api.registry.ResourceKey.parse("aprism:x");
+        reg.items().register(k,
+                new com.aprism.api.registry.ItemContent(k, 4));
+        GameContentBindingInstaller installer = new GameContentBindingInstaller(reg);
+        installer.setRemapProfile(true);
+        var results = installer.bindAll();
+        assertEquals("PROFILE_UNSUPPORTED", results.get(0).refusal());
+    }
+}

gradle.properties

@@ -2,7 +2,7 @@
 # Author: BlockConnect@StarsailsClover
 
 # Aprism version (public): v<Year>.<minor>[-Alpha.<n>]
-aprismVersion = v26.8-Alpha.4
+aprismVersion = v26.8-Alpha.5
 # Internal phase tracker (not shown in public version strings)
 aprismPhase = Phase0
 aprismGroup = com.aprism