Resolve adapters by what is mounted, and say why each kind is not loaded

runtime.py resolved adapters at 7 call sites and only ever looked in the
adapter library, so an adapter attached to a cartridge (cartridge.py:230
copies it into <cartridge>/adapters/{kind}/) was never loaded by anything.
Resolution now lives in adapters.py: it reads the mounted cartridge set,
prefers a mounted cartridge's copy over the library, and answers every one
of the six kinds with a state the facts support — loaded, available,
deferred (base_model mismatch or missing weights, both models named in the
reason), missing — plus a shadowed row for each adapter that lost the
choice. A mounted cartridge is the scenario selection; neither manifest
carries a scenario field, so none was invented.

Two bugs the new tests caught: the preference sort lost reverse=True, so a
library adapter beat a mounted cartridge's copy, and the load branch had
never been executed by a test. Stub weights now prove peft is asked to
attach, that the returned model is put in eval mode, and that the endpoint
reports loaded until unload clears it.

Faces: GET /api/runtime/adapters, `ely-eye adapters`, and a log line naming
the reason whenever a generation runs without an adapter.

Gates: 222 passed; ruff clean; mypy cold cache on the 7 touched files gives
the same 2 errors as HEAD's runtime.py, and pyright gives the same 2 as
HEAD — both are qwen_vl_utils typing artifacts (process_vision_info returns
2 or 3 values depending on return_video_kwargs; the product takes 2).

backend/src/ely_eye/proofs/checks_runtime.py

@@ -9,6 +9,7 @@ from __future__ import annotations
 from pathlib import Path
 from typing import Any
 
+from .. import adapters
 from ..compiler import ContextCompiler
 from ..config import Settings
 from ..db import Database
@@ -17,7 +18,7 @@ from ..evaluation_schemas import (
 )
 from ..evidence_graph import EvidenceGraphService
 from ..profiles import runtime_profile_report
-from ..runtime import QwenRuntime, resolve_runtime_adapter
+from ..runtime import QwenRuntime
 from ..schemas import (
     RuntimeProfile,
     TrainingAdapterKind,
@@ -58,7 +59,7 @@ class RuntimeChecks:
             return deferred
         runtime = QwenRuntime(self.settings)
         status = runtime.status()
-        adapter = resolve_runtime_adapter(self.settings)
+        adapter, _adapter_state, _adapter_reason = adapters.resolve_library_adapter(self.settings)
         weight_path = adapter.path / "adapter_model.safetensors" if adapter else None
         payload = {
             "runtime_status": status.model_dump(mode="json"),
@@ -133,7 +134,7 @@ class RuntimeChecks:
             )
             payload["generation_question"] = generation_question
             status = runtime.status()
-            adapter = resolve_runtime_adapter(proof_settings)
+            adapter, _adapter_state, _adapter_reason = adapters.resolve_library_adapter(proof_settings)
             generation = runtime.generate(generation_question, context)
             answer, citations, citation_report = Verifier().verify_answer(generation.text, context)
             claim_id = EvidenceGraphService(proof_settings, self.db).record_answer(