Add automatic scope resolution to Context Compactor tool

[sudo-deus]

Summary

The Context Compactor tool should support automatic scope resolution that matches the Context Compactor Injector filter.

Current behavior

The tool saves snapshots under the explicit scope_id passed to save_context_snapshot.

If scope_id is empty, the tool falls back to its own default_scope valve.

The filter, however, can resolve scope dynamically using scope_source, such as:

chat_id_or_default
folder_id_or_default
default_only

This can cause mismatches.

Example:

Tool saves snapshot under: test-context-compactor
Filter resolves current chat scope as: folder_abc123
Result: active snapshot is not injected

Shortcoming

The user must manually know and pass the same scope that the filter will later resolve.

This is error-prone, especially for folder-level context isolation, where the correct target scope may be:

folder_<folder_id>

The problem is more visible when using:

scope_source = folder_id_or_default
default_scope = unfiled

That mode is desirable because it keeps folder contexts isolated from each other and prevents unfiled chats from reading folder snapshots, but the tool does not yet help save snapshots into the matching folder scope.

Desired behavior

Add a helper function such as:

resolve_context_scope

or add an optional mode to save_context_snapshot, such as:

scope_id = ""
scope_source = "auto"

The tool should then resolve the same effective scope as the filter, if Open WebUI passes the needed metadata to tools.

Proposed implementation direction

If Open WebUI passes __metadata__, chat_id, and/or folder_id to tools in this environment, reuse the same scope-resolution logic as the filter:

chat_id_or_default
folder_id_or_default
default_only

For folder mode:

folder_id -> folder_<folder_id>
no folder -> default_scope

Recommended default for project isolation:

scope_source = folder_id_or_default
default_scope = unfiled

Acceptance criteria

• Tool can report the resolved effective scope before saving.
• save_context_snapshot can save to the automatically resolved scope.
• Filter and tool use matching scope-resolution behavior.
• Folder contexts remain isolated from each other.
• Unfiled chats use only the unfiled/default scope.
• Unfiled chats do not read folder snapshots.
• No external APIs, model calls, embeddings, databases, or tokenizer dependencies are introduced.