Record the knowledge snapshot on every Direct review plan

A review should record which knowledge it was served, so a finding can be
traced to the exact rules that were active (the knowledge service now swaps
snapshots at runtime).

- DirectReviewPlan gains knowledge_snapshot (the activated snapshot id,
  "packaged", or "unverified") and knowledge_tree_sha256 (the manifest tree
  hash of a verified snapshot, else empty). Every document read under the
  plan's review_context_id comes from that same snapshot. Both fields default
  to empty, so existing callers are unaffected.
- KnowledgeView.public_snapshot never exposes a development tree's absolute
  path. The old diagnostics value "unverified:/abs/path" leaked it into plans;
  diagnostics.knowledge_snapshot now uses the public form too.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: tzhouam

doc/architecture/SPEC/knowledge_view.md

@@ -31,3 +31,7 @@ stdlib + `.sdk._resources`。叶子模块。
 
 ## 测试
 `test_knowledge_view_routing.py`。
+
+## 2026-09-28 可记录的快照标识
+`public_snapshot`：激活快照 ID、`packaged` 或 `unverified`（开发树的绝对路径不外泄）；`tree_sha256`：已验证快照
+按清单重算的树哈希。`direct_routing` 的 `diagnostics.knowledge_snapshot` 与 SDK 计划都使用它们。

doc/architecture/SPEC/sdk.md

@@ -128,3 +128,8 @@ Direct 1.1 / Strict 1.3 accept typed `CarriedFinding` inputs (unique IDs, source
 ## 2026-09-28 trace/1 导出
 `sdk.v1` 导出 `TraceStore`、`TRACE_SCHEMA`、`trace_context`、`redact`（见 `trace_store.md`），RB 用同一 schema
 记录 review 的模型调用、判定与结果；导入它们不加载 `config`/`contract`/`mcp_server` 等私有模块。
+
+## 2026-09-28 计划携带知识快照
+`DirectReviewPlan` 新增 `knowledge_snapshot`（激活快照 ID、`packaged` 或 `unverified`，从不暴露开发树路径）
+与 `knowledge_tree_sha256`（已验证快照的清单树哈希，否则为空）。同一 `review_context_id` 下的文档读取都来自这份
+快照，RB 应随每次 review 记录这两个值。

src/infermatrix_copilot/direct_routing.py

@@ -687,7 +687,7 @@ def direct_review_plan(
             "if_missing": "partial_review",
         },
         "diagnostics": {
-            "knowledge_snapshot": view.snapshot,
+            "knowledge_snapshot": view.public_snapshot,
             "timing_ms": {
                 "routing": route_ms,
                 "execution_budget": budget_ms,

src/infermatrix_copilot/knowledge_view.py

@@ -62,6 +62,22 @@ def current(cls) -> "KnowledgeView":
     def verified(self) -> bool:
         return self.files is not None
 
+    @property
+    def public_snapshot(self) -> str:
+        """The snapshot id safe to record anywhere: the activated snapshot's id,
+        ``packaged``, or ``unverified`` (a development tree's path is never exposed)."""
+        return "unverified" if self.snapshot.startswith("unverified:") else self.snapshot
+
+    @property
+    def tree_sha256(self) -> str:
+        """The manifest tree hash of a verified snapshot ("" otherwise)."""
+        if self.files is None:
+            return ""
+        tree = hashlib.sha256()
+        for rel in sorted(self.files):
+            tree.update(f"{rel}\0{self.files[rel]}\n".encode("utf-8"))
+        return tree.hexdigest()
+
     def relative(self, path: str | Path) -> str:
         """Return the knowledge-relative id of an absolute path inside this view."""
         try:

src/infermatrix_copilot/sdk/v1/direct.py

@@ -378,6 +378,8 @@ def plan(self, request: DirectReviewRequest) -> DirectReviewPlan:
             completion_gate=completion_gate,
             diagnostics=dict(raw.get("diagnostics") or {}),
             carried_findings=request.carried_findings,
+            knowledge_snapshot=view.public_snapshot,
+            knowledge_tree_sha256=view.tree_sha256,
         )
         self._remember_context(review_context_id, expected_head, carried, view)
         return plan

src/infermatrix_copilot/sdk/v1/models.py

@@ -250,6 +250,10 @@ class DirectReviewPlan(_Serializable):
     completion_gate: dict[str, Any]
     diagnostics: dict[str, Any] = field(default_factory=dict)
     carried_findings: tuple[CarriedFinding, ...] = ()
+    # which knowledge this plan (and every document read under its
+    # review_context_id) was served from: record it with the review
+    knowledge_snapshot: str = ""
+    knowledge_tree_sha256: str = ""
 
 FeedbackStatus = Literal[
     "checked", "disabled", "unavailable", "not_applicable"

test/test_knowledge_view_routing.py

@@ -207,6 +207,10 @@ def test_sdk_completion_pins_the_plan_snapshot(tmp_path, monkeypatch):
         changed_paths=(ChangedPath(path="vllm_omni/core/sched/a.py"),),
     ))
     assert plan.diagnostics["knowledge_snapshot"] == "e" * 40
+    assert plan.knowledge_snapshot == "e" * 40
+    manifest = json.loads((old / "MANIFEST.json").read_text())
+    assert plan.knowledge_tree_sha256 == manifest["tree_sha256"]
+    assert plan.to_dict()["knowledge_snapshot"] == "e" * 40
 
     tmp_link = tmp_path / "active.tmp"
     tmp_link.symlink_to(new)
@@ -220,6 +224,21 @@ def test_sdk_completion_pins_the_plan_snapshot(tmp_path, monkeypatch):
     assert "provider resources changed after the review context was issued" not in decision.missing
 
 
+def test_plans_from_a_development_tree_never_expose_its_path(tmp_path, monkeypatch):
+    from infermatrix_copilot.sdk.v1 import ChangedPath, DirectClient, DirectReviewRequest, RepositoryRef
+
+    root = _copy_tree(tmp_path)
+    monkeypatch.setenv(KNOWLEDGE_ROOT_ENV, str(root))
+    _load_view.cache_clear()
+    plan = DirectClient().plan(DirectReviewRequest(
+        review_id="r3", repository=RepositoryRef(alias="vllm-omni"), pr_number=3,
+        expected_head_sha="3" * 40, title="scheduler fix", body="",
+        changed_paths=(ChangedPath(path="vllm_omni/core/sched/a.py"),),
+    ))
+    assert plan.knowledge_snapshot == "unverified" and plan.knowledge_tree_sha256 == ""
+    assert str(tmp_path) not in json.dumps(plan.to_dict())
+
+
 def test_sdk_document_reads_follow_the_plan_snapshot(tmp_path, monkeypatch):
     from infermatrix_copilot.sdk.v1 import (
         ChangedPath, DirectClient, DirectReviewRequest, RepositoryRef,