fix(arguments): route "חשב טיעונים" through the legal-analyst agent

The /aggregate-arguments endpoint ran an in-container BackgroundTask that
called claude_session (the local `claude` CLI) — which does not exist in the
FastAPI container. The button silently produced nothing, and on `force` it
destructively DELETEd existing arguments *before* the doomed LLM call.

Replace the inline task with the established delegation pattern used by
"חלץ עובדות שמאיות" (extract-appraiser-facts): a cheap in-container DB
pre-check (no_claims / exists), then a Paperclip wakeup of the company's
legal-analyst, which runs mcp__legal-ai__aggregate_claims_to_arguments
locally (where the CLI lives) and reports back. `force` now runs locally too,
so delete+recompute are atomic on the host — no more destructive failure.

Frontend: AggregateArgumentsResult becomes a discriminated union
(queued | no_claims | exists | skipped) and the toast is status-accurate
instead of the misleading fixed "refresh in a minute".

Invariants: G12 (Paperclip touch confined to paperclip_client behind the
agent_platform_port), G2 (replaces the broken path, no parallel capability),
engineering §6 (explicit statuses, no silent swallow).

UI change is logic/toast only (no visual-layout change) — within the
Claude-Design-gate bug-fix exemption. Richer inline status panels deferred
to the gate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/paperclip_client.py

@@ -1371,3 +1371,121 @@ async def wake_analyst_for_appraiser_facts(
         "analyst_id": analyst_id,
         "main_issue_id": main_issue_id,
     }
+
+
+async def wake_analyst_for_argument_aggregation(
+    case_number: str,
+    company_id: str,
+    force: bool = False,
+) -> dict:
+    """Wake the legal-analyst to aggregate raw claims into legal arguments.
+
+    Triggered by the chair clicking "חשב טיעונים" in the case page. The
+    FastAPI container cannot run `aggregate_claims_to_arguments` directly —
+    the aggregator calls `claude_session.query_json()`, which only works
+    where the local `claude` CLI is present (the MCP server / agent runner
+    on the host), **not in this container**. So instead of an in-container
+    BackgroundTask (which fails silently and, on `force`, destructively
+    deletes the existing arguments before the doomed LLM call), we create a
+    child issue under the case's main Paperclip issue, assign it to the
+    analyst of the correct company, and trigger a wakeup. The analyst's
+    HEARTBEAT picks up the issue, runs the MCP tool locally, and reports
+    back via a comment.
+
+    Mirrors ``wake_analyst_for_appraiser_facts`` — same delegation shape.
+
+    Returns a dict shaped for the FastAPI endpoint to serialize as-is:
+        {"status": "queued", "sub_issue_id", "analyst_id", "main_issue_id"}
+      or {"status": "skipped", "reason": "..."} for non-fatal early outs.
+    """
+    if not PAPERCLIP_BOARD_API_KEY:
+        logger.warning(
+            "PAPERCLIP_BOARD_API_KEY not set — cannot queue analyst wakeup "
+            "for argument aggregation on %s",
+            case_number,
+        )
+        return {"status": "skipped", "reason": "no_api_key"}
+
+    analyst_id = ANALYST_AGENTS.get(company_id)
+    if not analyst_id:
+        logger.info("No analyst configured for company %s — skipping", company_id)
+        return {"status": "skipped", "reason": "no_analyst", "company_id": company_id}
+
+    issues = await get_case_issues(case_number)
+    if not issues:
+        logger.warning(
+            "No Paperclip issues found for case %s — cannot queue analyst", case_number,
+        )
+        return {"status": "skipped", "reason": "no_issue"}
+
+    main_issue = next((i for i in issues if i.get("status") == "in_progress"), None) or issues[0]
+    main_issue_id = main_issue["id"]
+
+    force_clause = ", force=True" if force else ""
+    rerun_note = (
+        "זהו חישוב-מחדש (force) — הטיעונים הקיימים יימחקו ויחושבו מחדש.\n\n"
+        if force else ""
+    )
+    description = (
+        f"חיים ביקש חישוב טיעונים משפטיים בתיק {case_number}.\n\n"
+        f"{rerun_note}"
+        f"הרץ `mcp__legal-ai__aggregate_claims_to_arguments(case_number=\"{case_number}\"{force_clause})` "
+        f"וכתוב comment בעברית עם תוצאת האיגוד — כמה טיעונים מובחנים נוצרו לכל צד "
+        f"(עוררים / משיבים / ועדה / מבקשי-היתר). אם אין טענות גולמיות בתיק, דווח "
+        f"ב-comment שצריך להריץ קודם חילוץ טענות (`extract_claims`) וסגור את ה-issue כ-blocked."
+    )
+    child_resp = await pc_request(
+        "POST",
+        f"/api/issues/{main_issue_id}/children",
+        json={
+            "title": f"[ערר {case_number}] חישוב טיעונים משפטיים",
+            "description": description,
+            "status": "in_progress",
+            # Paperclip ISSUE_PRIORITIES = critical|high|medium|low — "normal"
+            # is NOT a valid enum value (Zod 400 → surfaces as 500).
+            "priority": "medium",
+            "assigneeAgentId": analyst_id,
+        },
+        raise_on_error=True,
+    )
+    sub_issue = child_resp.json()
+    sub_issue_id = sub_issue["id"]
+
+    # Tag plugin_state so the case page surfaces this sub-issue too.
+    try:
+        conn = await asyncpg.connect(PAPERCLIP_DB_URL)
+        try:
+            await _link_case_to_issue(conn, sub_issue_id, case_number)
+        finally:
+            await conn.close()
+    except Exception as e:
+        logger.warning("plugin_state link failed for sub_issue=%s: %s", sub_issue_id, e)
+
+    wake_resp = await pc_request(
+        "POST",
+        f"/api/agents/{analyst_id}/wakeup",
+        json={
+            "source": "on_demand",
+            "triggerDetail": "manual",
+            "reason": f"aggregate_arguments_{case_number}",
+            # "assignment" is the generic mutation the HEARTBEAT recognises;
+            # task intent lives in the child-issue description, not the payload.
+            "payload": {
+                "issueId": sub_issue_id,
+                "mutation": "assignment",
+                "caseNumber": case_number,
+            },
+        },
+        raise_on_error=True,
+    )
+    logger.info(
+        "Analyst wakeup for argument aggregation on case %s: sub_issue=%s "
+        "analyst=%s force=%s wake=%s",
+        case_number, sub_issue_id, analyst_id, force, wake_resp.status_code,
+    )
+    return {
+        "status": "queued",
+        "sub_issue_id": sub_issue_id,
+        "analyst_id": analyst_id,
+        "main_issue_id": main_issue_id,
+    }