feat: add scoped model runtime configuration

Introduce provider, model, and invocation contracts with encrypted configuration persistence. Add web runtime fencing, route fallback, recovery middleware, workspace scoping, and comprehensive tests.

tests/test_skill_context_middleware.py

@@ -0,0 +1,84 @@
+from __future__ import annotations
+
+from langchain.agents.middleware.types import ModelRequest
+from langchain_core.messages import HumanMessage
+
+from EvoScientist.middleware.skill_context import BudgetedSkillsMiddleware
+
+
+def _skill(name: str, description: str) -> dict[str, object]:
+    return {
+        "name": name,
+        "description": description,
+        "path": f"/skills/{name}/SKILL.md",
+        "allowed_tools": [],
+    }
+
+
+def _request(query: str, skills: list[dict[str, object]]) -> ModelRequest:
+    return ModelRequest(
+        model=object(),
+        messages=[HumanMessage(content=query)],
+        system_prompt="Base system prompt.",
+        state={"skills_metadata": skills},
+    )
+
+
+def test_skill_context_prefers_relevant_skill_and_omits_irrelevant_catalog():
+    middleware = BudgetedSkillsMiddleware(
+        backend=object(), sources=["/skills/"], max_skills=2, max_skills_bytes=1024
+    )
+    result = middleware.modify_request(
+        _request(
+            "请分析蛋白质结构预测结果",
+            [
+                _skill("protein-structure", "蛋白质结构预测和结果分析。"),
+                _skill("frontend-design", "Build polished user interfaces."),
+            ],
+        )
+    )
+
+    prompt = str(result.system_message.content)
+    assert "protein-structure" in prompt
+    assert "frontend-design" not in prompt
+    assert "query-relevant subset" in prompt
+
+
+def test_skill_context_enforces_count_and_utf8_budget():
+    middleware = BudgetedSkillsMiddleware(
+        backend=object(),
+        sources=["/skills/"],
+        max_skills=16,
+        max_skills_bytes=2048,
+        max_description_bytes=128,
+    )
+    skills = [
+        _skill(f"analysis-{index}", "analysis " + "x" * 1_000) for index in range(300)
+    ]
+
+    selected = middleware._select_skills(skills, "analysis")
+    rendered = middleware._format_budgeted_skills(selected)
+
+    assert len(selected) == 16
+    assert len(rendered.encode("utf-8")) <= 2048
+    assert "analysis-299" not in rendered
+
+
+def test_skill_context_does_not_fall_back_to_all_skills_without_a_match():
+    middleware = BudgetedSkillsMiddleware(backend=object(), sources=["/skills/"])
+    result = middleware.modify_request(
+        _request(
+            "unrelated request",
+            [_skill("protein-structure", "Protein folding workflow.")],
+        )
+    )
+
+    prompt = str(result.system_message.content)
+    assert "protein-structure" not in prompt
+    assert "query-relevant subset" in prompt
+
+
+def test_skill_context_accepts_a_single_skill_source():
+    middleware = BudgetedSkillsMiddleware(backend=object(), sources="/skills/")
+
+    assert middleware.sources == ["/skills/"]