[Doc] improve the documentation for the role of returns edges in the dfg

[EagleoutIce]

No description provided.

[Copilot]

Pull Request Overview

This PR enhances the documentation around how return edges and exit points are represented in both the Dataflow and Control Flow Graph wikis, plus a few small code cleanups.

• Added a “Working With Exit Points” section to the CFG wiki and updated generation timestamps.
• Enhanced the Dataflow Graph wiki with richer notes on Returns edges, anonymous function origins, and issue links.
• Consolidated imports and adjusted fallback behavior in the Mermaid DFG renderer; introduced UnnamedFunctionCallOrigin constant.

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
wiki/Control Flow Graph.md	Updated timestamps and added “Working With Exit Points” section
src/util/mermaid/dfg.ts	Merged imports and changed the default node-lexeme fallback value
src/documentation/print-dataflow-graph-wiki.ts	Reordered imports, added Returns-edge documentation and note blocks
src/documentation/print-cfg-wiki.ts	Added imports for edge names/assertions and new exit-points section
src/dataflow/internal/process/functions/call/unnamed-call-handling.ts	Added UnnamedFunctionCallOrigin and updated its usage

Comments suppressed due to low confidence (2)

src/documentation/print-cfg-wiki.ts:2372

• Correct 'exit points' to singular 'exit point' when referring to one marker.

Looking at the if vertex for (with id `5`) we see that it is again linked to a single exit points: `5-exit`.

src/dataflow/internal/process/functions/call/unnamed-call-handling.ts:16

• Consider adding or updating unit tests to verify that UnnamedFunctionCallOrigin is correctly emitted and consumed in processUnnamedFunctionCall.

export const UnnamedFunctionCallOrigin = 'unnamed';

[EagleoutIce]

This pull request is included in v2.2.13 (see Release v2.2.13 (Control-Flow Graph, R Graphics, and Better Aliasing)).