refactor(routes): move compare domain into routes/compare/ subpackage

[ydonghao]

Summary

Slice 2i of the route-domain reorganization (Refs #4082 / #4071; inventory baseline in #4148). Moves the compare domain into routes/compare/, keeping a backward-compat sys.modules shim at the old path. Pure file reorganization, no behavior change.

Follows the same pattern as the merged gallery (#4903), research (#4975), memory (#5007), history (#5090), contacts (#5227), and note (#5236) slices.

What moves

From	To
routes/compare_routes.py (365 lines)	routes/compare/compare_routes.py

New routes/compare/__init__.py marks the subpackage. Compare is a single-file, LOW-complexity domain.

Backward compatibility

A backward-compat shim remains at routes/compare_routes.py, using sys.modules replacement so the import ... as cr + monkeypatch.setattr(cr, "SessionLocal", ...) / "_owned_endpoint_by_url" / "_owned_endpoint_by_id" pattern in test_endpoint_owner_scope_followup.py reaches the canonical module.

The canonical module imports only from core/, src/, and routes.session_routes — no dependency on the legacy shim.

Test repoints (1 site)

One source-introspection test reads the compare source by file path. Repointed from routes/compare_routes.py → routes/compare/compare_routes.py:

• test_endpoint_owner_scope_followup.py (shared with other domains; only the compare entry repointed here)

Shim regression test

Adds tests/test_compare_routes_shim.py to pin the sys.modules shim contract (same-object).

How to test

python -m compileall routes/compare/ routes/compare_routes.py app.py
python -m pytest tests/ -q

Full suite: 4676 passed, 3 skipped, 0 failed.

Target branch

• This PR targets dev, not main.

Linked Issue

Follows the Phase 0 architecture refactor (#4082 / #4071) and the merged runtime inventory (#4148). One domain per PR per maintainer guidance.

Type of Change

• Refactor / cleanup

Checklist

• I searched open issues and open PRs — this is not a duplicate
• This PR targets dev
• My changes are limited to the scope described above — no unrelated refactors
• No runtime behavior changes (pure file move + import shim)
• Backward-compatible: old from routes.compare_routes import ... paths keep working via shim

[ydonghao]

Friendly ping for review 👋

This is slice 2i of the route-domain reorg, one of three parallel low-risk slices (the others: #5658 cleanup, #5659 admin_wipe). Only the compare domain moves — a single-file, 365-line domain — into routes/compare/ behind the same sys.modules shim as all previous slices.

Both points from your #4903 review are baked in (canonical doesn't depend on shim; shim regression test included). One source-introspection test site repointed (test_endpoint_owner_scope_followup.py). CI fully green (pytest 4676 passed).

@RaresKeY @alteixeira20 — would you mind taking a look when you have a moment?

[RaresKeY]

LGTM. I reviewed the latest head against the prior route-domain move pattern. The compare implementation is preserved byte-for-byte under the new canonical package path, app registration uses that path, and the legacy shim keeps old imports resolving to the same module object. I did not find any author-actionable issues.

Validation

• Visible CI checks on this head passed.
• Focused isolated tests passed (17 tests), the canonical-first legacy import probe passed, and the changed Python files compiled successfully.
• I did not run a live application smoke test.