Extend repo: namespace with AEM repository-api properties; clarify repo:id (#2213)

[cgoudie]

What this change does

Closes #2213.

The repository (repo:) namespace at http://ns.adobe.com/adobecloud/core/1.0 previously defined only repo:name, repo:path, repo:createDate, and repo:modifyDate. Adobe Experience Manager's repository API emits and consumes a substantially larger set of repo: properties, which until now had no authoritative definition in XDM.

This PR extends the core/1.0 Common Properties datatype to define the full set of repo: properties used by the repository API, grouped into composable definition blocks:

• Identity / descriptive: repo:id, repo:assetId, repo:assetClass, repo:repositoryId, repo:repositoryType, repo:etag, repo:size, repo:version, repo:state, repo:resource (plus existing repo:name, repo:path, dc:format)
• Dates: repo:discardDate, repo:expires, repo:lastPublishedTime (plus existing repo:createDate, repo:modifyDate)
• Actor: repo:createdBy, repo:modifiedBy, repo:discardedBy
• Hierarchy: repo:ancestors
• Access control: repo:owner, repo:acl (with nested repo:principal, repo:privileges, repo:relations, repo:modifier, repo:inheritance)
• Transfer / discovery: repo:resource, repo:md5, repo:blocksize, repo:accelerated, repo:availableRegions, repo:environment
• Dynamic Media (Scene7): repo:scene7Domain, repo:scene7File, repo:scene7FileStatus, repo:scene7Folder, repo:scene7FontStyle, repo:scene7FontType, repo:scene7LastModified, repo:scene7Name, repo:scene7RTFName, repo:scene7Type

Shape verification

Property shapes were verified two ways to avoid freezing an incorrect shape into the immutable core/1.0 namespace:

1. Read against the repository-api Jackson serialization code.
2. Confirmed against a live AEM as a Cloud Service instance.

Notable non-scalar shapes: repo:resource is an object ({repo:reltype, component_id, revision, etag}), repo:principal is a string or object ({@id, xdm:provider, @type}) depending on principal type, repo:owner is an object map, repo:modifier is the enum GRANT/DENY, repo:ancestors is a string array of asset ids, and repo:size/repo:blocksize are integers.

The conditional-request properties repo:if-match / repo:if-none-match are intentionally excluded: they are operation preconditions supplied on a request (an ETag the upload is made conditional on), not descriptive metadata of the stored resource.

repo:id clarification

repo:id was previously described only as an asset identifier, but it is used across Adobe products to identify different kinds of entities (assets, directories, and persons/principals). This PR redefines it as the generic identifier of an addressable repository entity and makes its relationship to the asset-scoped repo:assetId explicit, so that consumers and code-generation tooling stop conflating the two.

Breaking changes

None. All additions are optional properties; existing properties are unchanged. The only modifications to existing definitions are added titles/descriptions.

Checklist

• node bin/validate-schemas.js introduces no new validation failures (failing-example set identical to master)
• npm test passes (2406 passing)
• prettier --check clean on changed source files
• Documentation regenerated for the changed schema (docs/reference/datatypes/external/repo/common.schema.{json,md})
• common.example.1.json updated to exercise the new properties
• CHANGELOG.md updated