Add content overwrite support

[KoblerS]

Add Content Overwrite Support for Attachments

New Feature

✨ Introduces configurable content overwrite behavior for the @cap-js/attachments plugin. By default, attachment content is protected from being overwritten (returning a 409 Conflict error). Users can now opt-in to allow content overwrites on a per-composition basis using the @Capabilities.UpdateRestrictions.NonUpdateableProperties annotation.

Changes

• db/index.cds: Added default annotation @Capabilities.UpdateRestrictions.NonUpdateableProperties: [content] to the Attachments aspect, preventing content overwrites out of the box.

• srv/basic.js: Introduced the _isContentUpdateRestricted() helper method that inspects the @Capabilities.UpdateRestrictions.NonUpdateableProperties annotation on an attachment entity. The existing 409-conflict check in put() is now gated behind this helper, so the restriction is only enforced when the annotation includes content.

• srv/aws-s3.js, srv/azure-blob-storage.js, srv/gcp.js: Updated the put() upload guard in all three storage backends to call _isContentUpdateRestricted() before checking for an existing file, enabling overwrite behavior when the annotation allows it.

• tests/incidents-app/db/attachments.cds: Added a new overwritableAttachments composition annotated with @Capabilities.UpdateRestrictions.NonUpdateableProperties: [] for testing the opt-in overwrite scenario.

• tests/integration/attachments-non-draft.test.js: Added an integration test that verifies content can be successfully overwritten when the annotation is set to an empty array.

• README.md: Added a new Allow Overwriting Attachment Content section documenting the feature, including a CDS example and a note about runtime evaluation across storage backends. Also updated the Table of Contents.

• CHANGELOG.md: Documented the new feature under version 3.11.0.

• package.json: Bumped version from 3.10.0 to 3.11.0.

• 🔄 Regenerate and Update Summary

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PR Bot Information

Version: 1.19.15 | 📖 Documentation | 🚨 Create Incident | 💬 Feedback

• Output Template: Default Template
• Summary Prompt: Default Prompt
• File Content Strategy: Full file content
• LLM: anthropic--claude-4.6-sonnet
• Correlation ID: 5ade5400-2e74-11f1-9f6b-5a4534e5aad0
• Event Trigger: pull_request.opened

[hyperspace-insights]

The PR introduces a clean mechanism to allow content overwriting via annotation override, with consistent implementation across all storage backends (DB, S3, Azure, GCP). Three issues were identified: a subtle null-guard imprecision in _isContentUpdateRestricted, a SELECT.one bug that can miss existing content when multiple attachment IDs are checked in bulk, and a test that asserts the overwrite HTTP status but never validates that the stored content actually changed.

PR Bot Information

Version: 1.19.15 | 📖 Documentation | 🚨 Create Incident | 💬 Feedback

• File Content Strategy: Full file content
• Correlation ID: 8a5602e0-2e75-11f1-8f5a-b621bca23555
• Event Trigger: pull_request.ready_for_review
• LLM: anthropic--claude-4.6-sonnet

[hyperspace-insights]

The PR introduces content overwrite support via @Capabilities.UpdateRestrictions.NonUpdateableProperties, which is well-structured across all storage backends (DB, S3, Azure, GCP). The core logic in _isContentUpdateRestricted is sound and the test coverage for both the restricted and permissive cases is thorough. The three issues flagged are: an empty ### Fixed changelog section, a misleading inline comment about the default restriction behavior, and a potential mid-stream failure scenario on object stores when overwriting (no explicit cleanup of the old blob before the new upload begins). Please address these before merging.

PR Bot Information

Version: 1.19.15 | 📖 Documentation | 🚨 Create Incident | 💬 Feedback

• Event Trigger: pull_request.opened
• LLM: anthropic--claude-4.6-sonnet
• File Content Strategy: Full file content
• Correlation ID: 5ade5400-2e74-11f1-9f6b-5a4534e5aad0

[hyperspace-insights]

Bug: Empty ### Fixed section in CHANGELOG entry

The ### Fixed section for v3.11.0 has no content, leaving an empty heading. Either add a relevant fix entry or remove the section entirely.

Suggested change

	### Fixed
	## Version 3.11.0
	### Added
	- Support for controlling content overwrite behavior via `@Capabilities.UpdateRestrictions.NonUpdateableProperties`. By default, `content` is listed as non-updateable, preventing overwrites with a `409` error. Setting the annotation to an empty array (`[]`) on a specific attachment composition allows content to be overwritten.

Double-check suggestion before committing. Edit this comment for amendments.

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