Wire job execution view into DAP

[rentziass]

Part 2 of 2 of adding a job execution view for the DAP debugger. Stacks on #4470.

With the job view model introduced in the base PR, this PR is only about wiring that new view into the DAP flow.

The goal here is to make the debugger able to serve a stable synthetic job source and map pauses back onto that source, without mixing those transport and lifecycle concerns into the rendering model itself.

Splitting the work this way keeps the concerns separate:

• Add job execution view model #4470 introduces the rendered job view and how its lines are assigned
• this PR connects that new view to job initialization, post-step registration, stack traces, and DAP source requests

That makes this follow-up review mostly about integration: when the view is created, how it is surfaced through DAP, and how frames resolve back to the synthetic source.

Testing

cd src && ./dev.sh test

[rentziass]

These are the core changes.

[Copilot]

Pull request overview

This PR wires the new JobExecutionView synthetic job source into the DAP debugger flow so the debugger can serve a stable “execution.yml” source and map stack frames back to the correct rendered step lines (including predicted/registered post-steps and the synthetic “Complete job” row).

Changes:

• Initialize and maintain a session-scoped synthetic job source (JobExecutionView) and expose it via the DAP source request.
• Update DAP stackTrace handling to map current/completed frames to the synthetic source lines (including job-complete behavior).
• Add/extend L0 tests covering source responses, stack trace line mapping, predicted post-step claiming, and synthetic source path sanitization.

Show a summary per file

File	Description
src/Test/L0/Worker/DapMessagesL0.cs	Adds serialization coverage for DAP source request/response message types.
src/Test/L0/Worker/DapDebuggerL0.cs	Adds integration-style L0 tests validating synthetic source serving and stack frame line mapping behavior.
src/Runner.Worker/JobRunner.cs	Calls into the DAP debugger to initialize the synthetic job steps source once steps are known.
src/Runner.Worker/ExecutionContext.cs	Notifies the DAP debugger when a post-job step is registered so predicted steps can be claimed.
src/Runner.Worker/Dap/IDapDebugger.cs	Extends the debugger interface to accept job-step initialization and post-step registration notifications.
src/Runner.Worker/Dap/DapMessages.cs	Introduces DAP source request/response DTOs (SourceArguments, SourceResponseBody).
src/Runner.Worker/Dap/DapDebugger.cs	Implements job source initialization, post-step prediction/claiming, source request handling, and stack trace source/line mapping.

Copilot's findings

• Files reviewed: 7/7 changed files
• Comments generated: 2