Fix workflow stack traces (no more evalmachine)

[Copilot]

Don't mind the broken dev test. it seems a bit flaky and gets fixed properly down the PR stack

Workflow code executes in a VM context via runInContext(), which defaults to evalmachine.<anonymous> in stack traces, making debugging difficult:

Error: test error
    at addTenWorkflow (evalmachine.<anonymous>:451:9)
    at async ...

Fixes #151

Solution

This PR implements comprehensive source map support for workflow stack traces by:

1. Generating inline source maps in the intermediate workflow bundle
2. Providing meaningful filenames to the VM context via runInContext()
3. Remapping stack traces using inline source maps to show original source locations

Changes

Core Runtime

• packages/core/src/source-map.ts (NEW) - Source map remapping logic using @jridgewell/trace-mapping
• packages/core/src/workflow.ts - Use parseWorkflowName() to extract clean file paths and pass as filename parameter to runInContext()
• packages/core/src/runtime.ts - Apply source map remapping to workflow error logs

Builder Configuration

• packages/builders/src/base-builder.ts - Set intermediate workflow bundle to use sourcemap: 'inline' (the VM-executed code needs inline source maps)

Tests

• packages/core/src/workflow.test.ts - Added test for nested stack traces
• packages/core/e2e/e2e.test.ts - Added e2e test for cross-file error stack traces
• workbench/example/workflows/helpers.ts (NEW) - Test helper module for verifying cross-file stack traces
• workbench/example/workflows/99_e2e.ts - Added nestedErrorWorkflow and crossFileErrorWorkflow with helper functions

Dependencies

• Added @jridgewell/trace-mapping to @workflow/core for pure-JS source map processing (no WASM dependency)

Results

Before

Error: test error
    at addTenWorkflow (evalmachine.<anonymous>:451:9)

After - Simple Error

Error: test error
    at addTenWorkflow (example/workflows/99_e2e.ts:23:10)

After - Nested Functions (Same File)

Error: Error from deeply nested function
    at deepFunction (../example/workflows/99_e2e.ts:33:10)
    at middleFunction (../example/workflows/99_e2e.ts:37:4)
    at topLevelHelper (../example/workflows/99_e2e.ts:41:4)
    at addTenWorkflow (../example/workflows/99_e2e.ts:24:4)

After - Cross-File Errors (Imported Modules)

Error: Error from imported helper module
    at throwError (../example/workflows/helpers.ts:3:10)
    at callThrower (../example/workflows/helpers.ts:6:4)
    at crossFileErrorWorkflow (../example/workflows/99_e2e.ts:447:4)

Stack traces now correctly show:

• ✅ Actual source file paths (not evalmachine.<anonymous>)
• ✅ Correct function names
• ✅ Source-mapped line and column numbers
• ✅ Cross-file call chains with correct file paths for each frame

Testing

• All 186 unit tests pass (including new nested stack trace test)
• New e2e test validates cross-file error stack traces
• Tested with nested errors, cross-file imports, and complex call stacks

Fixes #151

---

This is part 1 of 3 in a stack made with GitButler:

•  3  Normalize Workbenches #283
•  2  Proper error stack propogating #280
•  1  Fix workflow stack traces (no more evalmachine) #256 👈

[changeset-bot]

🦋 Changeset detected

Latest commit: 8c93c65

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 11 packages

Name	Type
@workflow/builders	Patch
@workflow/core	Patch
@workflow/cli	Patch
@workflow/next	Patch
@workflow/nitro	Patch
@workflow/sveltekit	Patch
@workflow/web-shared	Patch
workflow	Patch
@workflow/world-testing	Patch
@workflow/nuxt	Patch
@workflow/ai	Patch

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Project	Deployment	Preview	Comments	Updated (UTC)
example-nextjs-workflow-turbopack	Ready	Preview	Comment	Nov 9, 2025 8:00pm
example-nextjs-workflow-webpack	Ready	Preview	Comment	Nov 9, 2025 8:00pm
example-workflow	Ready	Preview	Comment	Nov 9, 2025 8:00pm
workbench-nitro-workflow	Ready	Preview	Comment	Nov 9, 2025 8:00pm
workbench-nuxt-workflow	Ready	Preview	Comment	Nov 9, 2025 8:00pm
workbench-sveltekit-workflow	Ready	Preview	Comment	Nov 9, 2025 8:00pm
workbench-vite-workflow	Ready	Preview	Comment	Nov 9, 2025 8:00pm
workflow-docs	Ready	Preview	Comment	Nov 9, 2025 8:00pm

[TooTallNate]

Couple small nits/questions, but otherwise