feat(settings): Phase 2 — migrate to mountainash-settings.profiles + auth

[discreteds]

Summary

Phase 2 of the profiles-promotion initiative: mountainash-data now consumes the descriptor/registry/auth primitives promoted to mountainash-settings in Phase 1 (shipped as v26.4.0) rather than maintaining its own copy.

ConnectionProfile shrinks to a thin subclass of mountainash_settings.profiles.DescriptorProfile that adds the database-flavored output methods only. A typed BackendDescriptor(ProfileDescriptor) subclass retains the database-specific fields (default_port, connection_string_scheme, ibis_dialect, rides_on). A DATABASES_REGISTRY = Registry("databases") replaces the module-level dict.

External API byte-identical — every previously-exported name from mountainash_data.core.settings still resolves from the same import path; DATABASES_REGISTRY is the only addition.

Spec mapping

• Design spec: mountainash-settings/docs/superpowers/specs/2026-04-16-profiles-promotion-design.md
• Implementation plan: docs/superpowers/plans/2026-04-16-profiles-migration-data.md (9 tasks)
• Phase 1 PR: feat(profiles): promote descriptor/registry/auth machinery from mountainash-data — Phase 1 mountainash-settings#32

What shipped

6 commits:

1. f166679 refactor(settings): thin ConnectionProfile + DATABASES_REGISTRY wrapper
2. 3b707d4 refactor(settings): rewire imports to mountainash-settings.profiles + auth (bundles T3+T4 — ProfileDescriptor raises TypeError on unknown kwargs, so T3 couldn't stand alone without typed BackendDescriptor)
3. ca61558 chore(settings): add DATABASES_REGISTRY to public re-exports
4. 0521ebb test(settings): switch to shared descriptor_invariants_for helper
5. 050c5d2 test(settings): trim tests to data-specific cases; delete duplicates
6. 3a14977 docs: update CLAUDE.md settings section for mountainash-settings promotion

Files touched

Rewritten:

• src/mountainash_data/core/settings/profile.py — ~200 → ~90 lines. Keeps only to_driver_kwargs() / to_connection_string().
• src/mountainash_data/core/settings/registry.py — wraps Registry("databases"); preserves REGISTRY as a _RegistryDictView(Mapping) for back-compat (inherits .get() via ABC).

New:

• src/mountainash_data/core/settings/descriptor.py — BackendDescriptor(ProfileDescriptor) with 4 typed database-specific fields.
• src/mountainash_data/core/settings/auth/ — compatibility shim re-exporting from mountainash_settings.auth (not in original plan; preserves ~18 test imports of from mountainash_data.core.settings.auth import X. Can be deleted once no downstream uses the deep path).

Mechanical rewrites:

• 12 per-backend settings files — import swap only (.descriptor/.auth → mountainash_settings.profiles/.auth).
• 7 adapter files — method rename (_default_driver_kwargs → _default_kwargs, _auth_to_driver_kwargs → _auth_kwargs) per upstream API.

Tests:

• test_auth.py + test_auth_dispatch.py deleted (coverage now in mountainash-settings).
• test_descriptor.py / test_profile.py / test_registry.py trimmed to database-specific behaviour.
• test_descriptors_invariants.py now uses shared descriptor_invariants_for(DATABASES_REGISTRY) helper — 108 parametric cases (12 backends × 9 invariants).

Deviations from plan (pragmatic)

1. T3+T4 bundled — ProfileDescriptor raises TypeError (not AttributeError) on unknown kwargs, so backends couldn't instantiate their descriptors without the typed subclass.
2. auth/ compatibility shim — not in plan, added to preserve ~18 test imports without rewriting them. Small, limited surface.
3. Registry test seams (_snapshot_for_tests, _reset_for_tests as module-level wrappers) — delegates to upstream Registry instance methods.

All three cleared in final code review as well-bounded and principled.

Test plan

• hatch run test:test tests/test_unit/ — 427 passed, 5 skipped, 0 failures
• Final code review approved
• Reviewer: spot-check __all__ preservation against origin/develop
• Reviewer: confirm adapter method rename is consistent across all 7 files

Dependency

Requires mountainash-settings >= 26.4.0 (released). Sibling-path dep in hatch.toml is unchanged.

🤖 Generated with Claude Code

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[codecov]

Codecov Report

❌ Patch coverage is 85.33333% with 11 lines in your changes missing coverage. Please review.
✅ Project coverage is 54.48%. Comparing base (f83c195) to head (3a14977).
⚠️ Report is 8 commits behind head on develop.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/mountainash_data/core/settings/registry.py	71.87%	8 Missing and 1 partial ⚠️
src/mountainash_data/core/settings/auth/base.py	0.00%	1 Missing ⚠️
...rc/mountainash_data/core/settings/auth/dispatch.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop      #75      +/-   ##
===========================================
- Coverage    58.24%   54.48%   -3.77%     
===========================================
  Files           61       52       -9     
  Lines         2867     2641     -226     
  Branches       308      289      -19     
===========================================
- Hits          1670     1439     -231     
- Misses        1085     1093       +8     
+ Partials       112      109       -3     

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