refactor(api): remove dead Streamlit-era service layer and demo commands (#1054)

Delete api/client.py (synchronous httpx client calling the app's own
FastAPI server, a leftover from the removed Streamlit UI) and the 13
api/*_service.py wrappers around it. None of these files had any
importer in routers, commands or tests, verified by grepping the whole
repo for each module name.

Also remove commands/example_commands.py (process_text/analyze_data
demo commands from the surreal-commands README) and its export from
commands/__init__.py, and update remaining docstring examples to
reference the real generate_podcast command.

The real services (command_service, credentials_service,
podcast_service) are untouched.

Author: lfnovo

CHANGELOG.md

@@ -10,6 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 - Release confidence process, documented and executable: `.github/RELEASE_PROCESS.md` now covers the risk-based test matrix (buckets A/B/C), the Docker image gate, the fix-loop re-test policy and the communication/credits/retro structure, backed by a new decision record (ADR-005) and versioned tooling under `scripts/release-test/` — `make release-test TAG= OLD_TAG=` runs fresh-install + upgrade scenarios against real images, and `make release-stack TAG= [DUMP=]` boots a browsable, isolated release-candidate stack (optionally with a copy of dev data) for manual verification
 
+### Removed
+- Dead Streamlit-era service layer (~2,000 lines): `api/client.py` (a synchronous HTTP client that called the app's own API) and 13 `api/*_service.py` wrappers that consumed the app's own HTTP API — none were imported by any router, command or test. Also removed the toy `process_text`/`analyze_data` demo commands (`commands/example_commands.py`) from the background worker
+
 ## [1.11.0] - 2026-07-11
 
 ### Added