feat: delete collections features

[mattjohnsonpint]

The Modus "Collections" feature will no longer be available with Modus v0.18 and newer. If you have an app that uses this feature, please contact us at [email protected] to discuss alternatives.

This PR deletes the Collections feature from Modus.

[linear]

HYP-3437 Remove Collections feature from Modus

[Copilot]

Pull Request Overview

This pull request completely removes the Collections feature from Modus in preparation for version v0.18 and newer. The deletions include source code, test files, manifest definitions, and configuration references related to collections.

• Removed collections interfaces, implementations, and corresponding tests.
• Updated manifest files, go.work, launch configurations, and CHANGELOG.

Reviewed Changes

Copilot reviewed 69 out of 69 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
runtime/collections/index/interfaces/interfaces.go	Deleted collections interfaces definitions.
runtime/collections/index/index.go	Deleted collections index definitions.
runtime/collections/index/helper.go	Deleted helper functions for collections.
runtime/collections/in_mem/text_index_test.go	Removed test cases for in-memory collections text index.
runtime/collections/in_mem/text_index.go	Deleted in-memory text index implementation.
runtime/collections/in_mem/sequential/vector_index_test.go	Removed tests for sequential vector index.
runtime/collections/in_mem/sequential/vector_index.go	Deleted sequential vector index implementation.
runtime/collections/in_mem/hnsw/vector_index_test.go	Removed tests for HNSW vector index.
runtime/collections/in_mem/hnsw/vector_index.go	Deleted HNSW vector index implementation.
runtime/collections/factory.go	Deleted collections factory code.
runtime/collections/collection.go	Deleted collections definitions.
lib/manifest/test/valid_modus.json	Removed collections section from the manifest test file.
lib/manifest/test/manifest_test.go	Deleted collection references from manifest tests.
lib/manifest/modus_schema.json	Removed collections definitions from the schema.
lib/manifest/manifest.go	Deleted collections fields from manifest parsing.
lib/manifest/collection.go	Deleted collection info types.
go.work	Removed collections example reference.
CHANGELOG.md	Updated changelog to document collections deletion.
.vscode/launch.json	Removed collections example configuration.
.trunk/configs/cspell.json	Removed collections-related terms.