[MaximHammer]

Summary

Adds the Impulse App to this repo. It's a Databricks App for building Impulse reports step by step or with an assistant: it generates the report notebook, runs it as a serverless job and charts the results. The app is optional and self-contained. The databricks-impulse package, the framework tests and the framework CI don't change.

Changes

• app/: the app, moved here from its own repository (without its history). It pins Impulse 0.10.0
• .github/workflows/app.yml: a separate, non-required check for the app. It runs on PRs that change the app, and on main after framework changes, so framework PRs and their Codecov status aren't affected.
• Skills: app/skills/impulse/ is a copy of skills/ from the pinned release. Framework skills are still edited only in skills/, and the app's CI fails if the copy differs from that release.
• Docs: a new "Impulse App" section under /app (overview, requirements, install, architecture) and a button on the landing page. Existing /docs links stay the same.
• README and CONTRIBUTING: short pointers to the app.

Testing

• Unit tests added/updated: the app's unit tests and contract tests pass. The contract tests check every generated notebook against both the 0.10.0 release and the framework code in this repo.
• Manual testing completed: deployed to a dev workspace. The app starts and serves its UI and API, and a sample report runs successfully on serverless.
• Documentation updated: the docs build passes with strict link checks.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.30%. Comparing base (e3daaa4) to head (c1b7760).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #132   +/-   ##
=======================================
  Coverage   90.30%   90.30%           
=======================================
  Files          68       68           
  Lines        6068     6068           
  Branches      758      758           
=======================================
  Hits         5480     5480           
  Misses        466      466           
  Partials      122      122           

Flag	Coverage Δ
query_engine	86.80% <ø> (ø)
reporting	94.92% <ø> (ø)

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🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[tombonfert]

1. Validate report names in the /api/reports/{name} routes (app/server/routes/reports.py)

The name path parameter is never checked against NAME_RE, but store.delete and runs.delete build workspace paths from it and delete them with recursive=True. A request like DELETE /api/reports/%2E%2E deletes:

• /Users/{email}/Impulse/.., which is the user's home folder (user token)
• /Users/{sp}/Impulse/{email}/.., which holds every user's published notebooks (service principal)

The get, put, runs and results routes have the same gap. Today only chat._report validates the name. I'd suggest validating it once for all routes, for example:

ReportName = Annotated[str, Path(pattern=NAME_RE.pattern)]

FastAPI then rejects bad names with a 422 before the handler runs.

2. Move the app to apps/adhoc-reporting/

We may build more apps on top of Impulse in the future, so each one should get its own folder under apps/. Please move app/ to apps/adhoc-reporting/ and update the docs and CI paths to match.

[tombonfert]

LGTM!