refactor: 精简标准 Skill 包模型

- 统一使用 SKILL.md 与通用资源表达

- 删除仓储、专用资源类型和低价值兼容接口

- 保留安全 ZIP 编解码、校验和内容存储能力

easy-agents-skill/src/main/java/com/easyagents/skill/codec/ZipSkillPackageCodec.java

@@ -4,7 +4,6 @@ import com.easyagents.skill.exception.SkillPackageException;
 import com.easyagents.skill.exception.SkillValidationException;
 import com.easyagents.skill.model.Skill;
 import com.easyagents.skill.model.SkillDocument;
-import com.easyagents.skill.model.SkillMetadata;
 import com.easyagents.skill.model.SkillPackage;
 import com.easyagents.skill.model.SkillPackageLayout;
 import com.easyagents.skill.model.SkillPackageLimits;
@@ -22,7 +21,6 @@ import com.easyagents.skill.validation.SkillValidationIssue;
 import com.easyagents.skill.validation.SkillValidationMode;
 import com.easyagents.skill.validation.SkillValidationReport;
 import com.easyagents.skill.validation.SkillValidationSeverity;
-import com.easyagents.skill.validation.SkillValidator;
 import com.easyagents.skill.validation.defaults.DefaultSkillValidator;
 import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
 import org.apache.commons.compress.archivers.zip.ZipFile;
@@ -62,7 +60,7 @@ import java.util.zip.ZipOutputStream;
 /**
  * 标准 Skill ZIP 的安全双向流式 Codec。
  */
-public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
+public class ZipSkillPackageCodec implements AutoCloseable {
 
     private static final String DEFAULT_MEDIA_TYPE = "application/octet-stream";
     private static final int CENTRAL_DIRECTORY_HEADER_SIZE = 46;
@@ -79,7 +77,6 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
     private static final int UINT16_MAX = 0xFFFF;
 
     private final SkillContentStore contentStore;
-    private final SkillValidator additionalValidator;
     private final boolean ownsContentStore;
 
     /**
@@ -88,7 +85,7 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
      * <p>该实例拥有默认内容存储，使用完毕后应调用 {@link #close()} 清理临时内容。</p>
      */
     public ZipSkillPackageCodec() {
-        this(new TemporaryFileSkillContentStore(), null, true);
+        this(new TemporaryFileSkillContentStore(), true);
     }
 
     /**
@@ -97,36 +94,17 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
      * @param contentStore 二进制内容存储
      */
     public ZipSkillPackageCodec(SkillContentStore contentStore) {
-        this(contentStore, null, false);
+        this(contentStore, false);
     }
 
-    /**
-     * 创建 ZIP Codec。
-     *
-     * @param contentStore 二进制内容存储
-     * @param validator Skill 聚合校验器
-     */
-    public ZipSkillPackageCodec(SkillContentStore contentStore, SkillValidator validator) {
-        this(contentStore, requireValidator(validator), false);
-    }
-
-    private ZipSkillPackageCodec(SkillContentStore contentStore, SkillValidator validator,
-                                 boolean ownsContentStore) {
+    private ZipSkillPackageCodec(SkillContentStore contentStore, boolean ownsContentStore) {
         if (contentStore == null) {
             throw new SkillPackageException("Skill content store is required.");
         }
         this.contentStore = contentStore;
-        this.additionalValidator = validator;
         this.ownsContentStore = ownsContentStore;
     }
 
-    private static SkillValidator requireValidator(SkillValidator validator) {
-        if (validator == null) {
-            throw new SkillPackageException("Skill validator is required.");
-        }
-        return validator;
-    }
-
     /**
      * 关闭 Codec 自有的默认临时内容存储。
      *
@@ -139,19 +117,6 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
         }
     }
 
-    /**
-     * 使用兼容入口导入 ZIP。
-     *
-     * @param inputStream ZIP 输入流
-     * @return Skill 列表
-     * @deprecated 请使用 {@link #decode(InputStream, SkillPackageReadOptions)}。
-     */
-    @Deprecated
-    @Override
-    public List<Skill> importZip(InputStream inputStream) {
-        return decode(inputStream, SkillPackageReadOptions.defaults()).getSkillPackage().getSkills();
-    }
-
     /**
      * 安全解码 Skill ZIP。
      *
@@ -159,7 +124,6 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
      * @param options 读取选项
      * @return 解码结果
      */
-    @Override
     public SkillPackageReadResult decode(InputStream inputStream, SkillPackageReadOptions options) {
         if (inputStream == null) {
             throw packageError("ZIP_INPUT_REQUIRED", null, "ZIP input stream is required.");
@@ -221,7 +185,6 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
      * @param options 写出选项
      * @return 编码结果
      */
-    @Override
     public SkillPackageWriteResult encode(SkillPackage skillPackage, OutputStream outputStream,
                                           SkillPackageWriteOptions options) {
         if (skillPackage == null || skillPackage.getSkills() == null || skillPackage.getSkills().isEmpty()) {
@@ -370,9 +333,7 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
             throw validationPackageError(e,
                     layout == SkillPackageLayout.ROOT_SKILL ? null : group.root);
         }
-        Map<String, Object> frontmatter = document.getFrontmatter().getValues();
-        String name = scalar(frontmatter.get("name"));
-        String description = scalar(frontmatter.get("description"));
+        String name = scalar(document.getFrontmatter().get("name"));
 
         List<SkillResource> resources = new ArrayList<>();
         for (ArchiveFile file : group.files) {
@@ -385,14 +346,9 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
         resources.sort(Comparator.comparing(SkillResource::getPath));
 
         Skill skill = new Skill();
-        skill.setId(null);
         skill.setPackageRoot(layout == SkillPackageLayout.ROOT_SKILL ? name : group.root);
-        skill.setName(name);
-        skill.setDescription(description);
-        skill.setMetadata(new SkillMetadata(frontmatter));
         skill.setDocument(document);
         skill.setResources(resources);
-        SkillResources.refreshLegacyViews(skill);
         return skill;
     }
 
@@ -400,7 +356,7 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
                                        StageTracker stages) throws IOException {
         SkillResourceKind kind = SkillResources.classify(file.relativePath);
         String mediaType = detectMediaType(file.relativePath);
-        boolean text = SkillResources.isText(file.relativePath, kind, mediaType);
+        boolean text = SkillResources.isText(file.relativePath, mediaType);
         long singleLimit = text ? limits.getMaxTextFileBytes() : limits.getMaxBinaryFileBytes();
         if (file.entry.getSize() > singleLimit) {
             throw packageError(text ? "TEXT_FILE_SIZE_LIMIT" : "BINARY_FILE_SIZE_LIMIT", file.fullPath,
@@ -489,24 +445,16 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
     }
 
     /**
-     * 执行 Codec 不可绕过的标准安全校验，并追加调用方业务校验。
+     * 执行 Codec 不可绕过的标准安全校验。
      *
      * @param skill Skill 聚合
      * @param limits 当前读写操作限额
      * @param mode 标准校验模式
-     * @return 合并后的结构化报告
+     * @return 结构化报告
      */
     private SkillValidationReport validateForCodec(Skill skill, SkillPackageLimits limits,
                                                    SkillValidationMode mode) {
-        SkillValidationReport report = new DefaultSkillValidator(limits)
-                .validateReport(skill, limits, mode);
-        if (additionalValidator != null) {
-            SkillValidationReport additionalReport = additionalValidator.getClass() == DefaultSkillValidator.class
-                    ? additionalValidator.validateReport(skill, null, mode)
-                    : additionalValidator.validateReport(skill, limits, mode);
-            report.merge(additionalReport);
-        }
-        return report;
+        return new DefaultSkillValidator(limits).validateReport(skill, limits, mode);
     }
 
     private List<OutputFile> prepareOutput(List<Skill> skills, SkillPackageLimits limits) {
@@ -557,7 +505,7 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
             files.add(OutputFile.text(skillPath, skillContent));
             totalSize = checkedOutputTotal(totalSize, skillSize, limits, skillPath);
 
-            List<SkillResource> resources = SkillResources.canonicalResources(skill);
+            List<SkillResource> resources = new ArrayList<>(skill.getResources());
             resources.sort(Comparator.comparing(SkillResource::getPath));
             for (SkillResource resource : resources) {
                 String path = skill.getName() + "/" + SkillPaths.normalize(resource.getPath());
@@ -1533,22 +1481,27 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
             }
             SkillPackageException rollbackFailure = null;
             for (int index = records.size() - 1; index >= 0; index--) {
+                StageRecord record = records.get(index);
+                if (record.cleaned) {
+                    continue;
+                }
                 try {
-                    contentStore.rollback(records.get(index).stage);
+                    contentStore.rollback(record.stage);
+                    record.cleaned = true;
                 } catch (RuntimeException cleanupError) {
                     if (rollbackFailure == null) {
                         rollbackFailure = new SkillPackageException(
-                                "SKILL_CONTENT_ROLLBACK_ERROR", records.get(index).path,
+                                "SKILL_CONTENT_ROLLBACK_ERROR", record.path,
                                 "Failed to rollback staged Skill package content.", cleanupError);
                     } else {
                         rollbackFailure.addSuppressed(cleanupError);
                     }
                 }
             }
-            finalized = true;
             if (rollbackFailure != null) {
                 throw rollbackFailure;
             }
+            finalized = true;
         }
 
         private void cleanupAfterFailure(Throwable primary) {
@@ -1557,17 +1510,21 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
             }
             for (int index = records.size() - 1; index >= 0; index--) {
                 StageRecord record = records.get(index);
+                if (record.cleaned) {
+                    continue;
+                }
                 try {
                     if (record.committedRef == null) {
                         contentStore.rollback(record.stage);
                     } else {
                         contentStore.release(record.committedRef);
                     }
+                    record.cleaned = true;
                 } catch (RuntimeException cleanupError) {
                     primary.addSuppressed(cleanupError);
                 }
             }
-            finalized = true;
+            finalized = records.stream().allMatch(record -> record.cleaned);
         }
     }
 
@@ -1577,6 +1534,7 @@ public class ZipSkillPackageCodec implements SkillPackageCodec, AutoCloseable {
         private final SkillResource resource;
         private final String path;
         private String committedRef;
+        private boolean cleaned;
 
         private StageRecord(SkillContentStage stage, SkillResource resource, String path) {
             this.stage = stage;