refactor(server): extract the artist-alias routes into routers/artist_aliases.py (R3)

[byrongamatos]

Second router in the R3 train, after audio-effects (#834). Move-only, backend-only.

Picked by measurement

router_scan.py ranks the artist-aliases / Tidy-up (P4) group at 0 monkeypatch.setattr targets and 0 helpers to relocate — its only dependencies are JSONResponse, app, and meta_db. 5 routes, all meta_db-only:

• GET /api/artist-aliases · GET /api/artists/raw · POST /api/artist-aliases · POST /api/artist-aliases/merge · DELETE /api/artist-aliases/{raw_name:path}

What changed

Bodies verbatim. Two mechanical edits: @app.<m> → @router.<m>, meta_db → appstate.meta_db (a module attribute at call time, so a re-imported server re-publishes a fresh DB into the seam). include_router mounts at the original site.

server.py: 9,386 → 9,337.

Verification

• Route table identical to origin/main — 143 routes, same paths/methods/registration order.
• No test retargeting: test_artist_alias drives via TestClient(server.app) + server.meta_db, neither of which moved. 18 tests pass.
• Boot smoke drives all 5 routes end-to-end: set ACDC → AC/DC, read it back, 400 on missing fields, delete.
• pytest 2398 passed; packaging guard green (tests/test_packaging.py sees the new router); pyflakes clean; JSONResponse still used in server.py (didn't go dead); npm run lint 0 errors.
• Codex preflight: 0 findings.

🤖 Generated with Claude Code

Summary by CodeRabbit

• New Features
  • Added/organized artist alias management endpoints (view, create/upsert, merge, delete) with validation and conflict handling.
  • Added an endpoint to browse raw artist names with song counts and canonical selections.
• Refactor
  • Moved artist alias route handling into a dedicated router module and mounted it at the existing route location.
• Documentation
  • Updated the changelog with progress on backend route-layer extraction.
  • Updated static size exemption line-count metrics in the documentation.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: db835fef-1b3a-4be7-9d5f-522dc4b0c9ac

📥 Commits

Reviewing files that changed from the base of the PR and between e572a0a and ede9bae.

📒 Files selected for processing (1)

• docs/size-exemptions.md

✅ Files skipped from review due to trivial changes (1)

• docs/size-exemptions.md

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📝 Walkthrough

Walkthrough

The artist alias API routes were extracted from server.py into lib/routers/artist_aliases.py, where they use APIRouter and appstate.meta_db. server.py mounts the new router, while changelog and size-exemption records are updated.

Changes

Artist aliases API extraction

Layer / File(s)	Summary
Artist alias router endpoints lib/routers/artist_aliases.py	Adds GET, POST, merge, and DELETE handlers for artist aliases and raw artists, including validation and database operations.
Router mounting and extraction records server.py, CHANGELOG.md, docs/size-exemptions.md	Mounts the extracted router in server.py and updates the changelog and recorded frontend line count.

Estimated code review effort: 2 (Simple) | ~10 minutes

Possibly related PRs

• got-feedBack/feedBack#833: Added the appstate router-seam wiring used by the extracted module.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: extracting the artist-alias routes from server.py into routers/artist_aliases.py.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch refactor/r3-router-artist-aliases

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@docs/size-exemptions.md`:
- Line 58: Update the rationale for the 9,337 size count in
docs/size-exemptions.md to credit both router extractions, explicitly mentioning
this PR’s artist_aliases extraction alongside the first routers module.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: d9e1ce5b-8a32-4233-b07e-26b5b0662d85

📥 Commits

Reviewing files that changed from the base of the PR and between b321569 and e572a0a.

📒 Files selected for processing (4)

• CHANGELOG.md
• docs/size-exemptions.md
• lib/routers/artist_aliases.py
• server.py