feat: online verification, node removals, and knowledge browser

Adds claim-bound online evidence records and citation verification scripts,
node removal transport/adapter, retrieval benchmark and owner-review tooling,
GraphCanvas/SourceDetail knowledge browser UI, and the ingest handoff helper.
Bumps the agents/gewu pack to the online-verification branch.

scripts/build_owner_review_packet.py

@@ -0,0 +1,126 @@
+#!/usr/bin/env python3
+"""Render held ingestion drafts and correction proposals as an owner decision sheet."""
+
+from __future__ import annotations
+
+import argparse
+import json
+from pathlib import Path
+from typing import Any
+
+
+def render(items: list[dict[str, Any]]) -> str:
+    sections = [
+        "# GEWU owner review sheet",
+        "",
+        (
+            "Mark one decision for each item and add a short rationale. This sheet records review "
+            "intent only; it does not alter GEWU state or grant acceptance authority."
+        ),
+        "",
+        (
+            "For held drafts: choose keep held, request revision, or initiate the authorized owner "
+            "challenge workflow. For corrections: choose approve for fresh owner workflow, request "
+            "revision, or reject. Proposal base commits may be stale; every later action must "
+            "context and re-evaluate the proposal."
+        ),
+        "",
+    ]
+    for index, item in enumerate(items, start=1):
+        proposal = item.get("proposal", {})
+        operations = proposal.get("operations", [])
+        nodes = [operation["node"] for operation in operations if operation.get("node")]
+        edges = [operation["edge"] for operation in operations if operation.get("edge")]
+        node = nodes[0] if nodes else {}
+        is_correction = item.get("source_stage") == "supersession"
+        kind = "Correction proposal" if is_correction else "Policy-held draft"
+        proposal_id = proposal.get("proposal_id", "unknown")
+        revision = proposal.get("revision", "?")
+        node_id = node.get("node_id", "not available")
+        node_type = node.get("node_type", "unknown")
+        sections.extend(
+            [
+                f"## {index}. {kind}: {node.get('title', proposal.get('proposal_id', 'Untitled'))}",
+                "",
+                f"- Proposal: `{proposal_id}` revision {revision}",
+                f"- Current state: {item.get('storage_state', 'evaluated; needs-review')}",
+                f"- Proposal base commit: `{proposal.get('base_commit', 'unknown')}`",
+                f"- Node: `{node_id}` ({node_type})",
+                f"- Summary: {node.get('summary', 'No summary recorded.')}",
+                "",
+                "### Claims and attached evidence",
+                "",
+            ]
+        )
+        claim_groups = [
+            ("Claim", node.get("claims", [])),
+            ("Assumption", node.get("assumptions", [])),
+            ("Limitation", node.get("limitations", [])),
+        ]
+        if not any(claims for _, claims in claim_groups):
+            sections.append("No node claim payload was included in this review item.")
+            sections.append("")
+        for group_label, claims in claim_groups:
+            for claim in claims:
+                sections.extend(
+                    [
+                        f"- **{group_label} {claim.get('claim_id', 'claim')}:** "
+                        f"{claim.get('text', '')}"
+                    ]
+                )
+                for evidence in claim.get("evidence", []):
+                    locator = evidence.get("locator", {})
+                    location = ", ".join(
+                        f"{key}={locator[key]}"
+                        for key in ("page", "block_id", "start", "end")
+                        if key in locator
+                    )
+                    quote = evidence.get("quote", "").splitlines()
+                    sections.append(
+                        f"  - Evidence `{evidence.get('source_revision_id', '?')}` ({location}):"
+                    )
+                    sections.extend(f"    > {line}" for line in quote)
+        for edge in edges:
+            sections.append(
+                f"- Supersession edge: `{edge.get('source', {}).get('id', '?')}` → `"
+                f"{edge.get('target', {}).get('id', '?')}` "
+                f"({edge.get('edge_type', 'relationship')})"
+            )
+        sections.extend(["", "### Owner decision", ""])
+        if is_correction:
+            sections.extend(
+                [
+                    "- [ ] Approve this replacement for the owner workflow "
+                    "(fresh evaluation still required)",
+                    "- [ ] Request revision",
+                    "- [ ] Reject this correction",
+                ]
+            )
+        else:
+            sections.extend(
+                [
+                    "- [ ] Keep held; do not create an exception",
+                    "- [ ] Request revision",
+                    "- [ ] Initiate the authorized owner challenge workflow",
+                ]
+            )
+        sections.extend(["- Rationale: ", "", "---", ""])
+    return "\n".join(sections)
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--input", type=Path, required=True)
+    parser.add_argument("--output", type=Path, required=True)
+    args = parser.parse_args()
+    items = json.loads(args.input.read_text(encoding="utf-8"))
+    if not isinstance(items, list) or len(items) != 19:
+        parser.error("Expected the frozen 19-item held-draft and correction review packet")
+    output = render(items)
+    with args.output.open("x", encoding="utf-8") as stream:
+        stream.write(output)
+    print(json.dumps({"status": "created", "items": len(items), "output": str(args.output)}))
+
+
+if __name__ == "__main__":
+    main()