feat(reports): wire run-now, archive, test-email, last-run status into the UI

Backend (reports router):
- POST /reports/test-email — send a test email (body/config recipients; dry-run
  if SMTP unset) to verify the relay.
- GET  /reports/list — list generated report artifacts on disk (newest first).
- GET  /reports/archive/{date} — serve a saved report.html (traversal-guarded).

Frontend (sound project header modals):
- Night Report modal: "Run & Email" button (POST /run) + a "Recent reports" list
  (GET /list → opens the archived report.html in a new tab).
- Settings modal: schedule + last-run status line, and a "Send test email" button.

Verified: endpoints (run→list→archive, traversal blocked, test-email recipient
fallback) and the template renders with all four wired + gated to sound projects.

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

backend/routers/reports.py

@@ -17,10 +17,12 @@ baseline-week range to populate the comparison.
 from __future__ import annotations
 
 import logging
-from datetime import datetime, timedelta, date
-from typing import Optional
-
+import re
 import uuid
+from datetime import datetime, timedelta, date
+from html import escape
+from pathlib import Path
+from typing import Optional
 
 from fastapi import APIRouter, Depends, HTTPException, Query, Request
 from fastapi.responses import HTMLResponse
@@ -202,3 +204,79 @@ async def run_nightly_report_endpoint(
         + (f"&metrics={','.join(metric_keys)}")
     )
     return result
+
+
+# ============================================================================
+# Test email + generated-report archive
+# ============================================================================
+
+_DATE_RE = re.compile(r"^\d{4}-\d{2}-\d{2}$")
+
+
+@router.post("/test-email")
+async def send_test_email(project_id: str, request: Request, db: Session = Depends(get_db)):
+    """Send a small test email to verify the SMTP relay (dry-run if unconfigured).
+
+    Recipients: JSON body {"recipients": "..."} overrides; else the project's
+    configured recipients; else the REPORT_SMTP_RECIPIENTS env default.
+    """
+    project = db.query(Project).filter_by(id=project_id).first()
+    if not project:
+        raise HTTPException(status_code=404, detail="Project not found")
+    try:
+        data = await request.json()
+    except Exception:
+        data = {}
+
+    raw = (data or {}).get("recipients")
+    if not raw:
+        cfg = db.query(SoundReportConfig).filter_by(project_id=project_id).first()
+        raw = cfg.recipients if cfg else None
+    recipients = None
+    if raw:
+        if isinstance(raw, list):
+            raw = ",".join(raw)
+        recipients = [r.strip() for r in raw.split(",") if r.strip()]
+
+    from backend.services.report_email import send_report_email
+    body = (
+        "<div style=\"font:14px Arial,sans-serif\">"
+        f"Terra-View test email for <b>{escape(project.name)}</b>.<br>"
+        "If you got this, the nightly sound-report email path is working.</div>"
+    )
+    return send_report_email("Terra-View — nightly report test email", body, recipients=recipients)
+
+
+@router.get("/list")
+async def list_reports(project_id: str, db: Session = Depends(get_db)):
+    """List the generated report artifacts on disk for this project (newest first)."""
+    if not db.query(Project).filter_by(id=project_id).first():
+        raise HTTPException(status_code=404, detail="Project not found")
+    base = Path("data/reports") / project_id
+    out = []
+    if base.exists():
+        for d in sorted((p for p in base.iterdir() if p.is_dir()), key=lambda p: p.name, reverse=True):
+            html_file = d / "report.html"
+            if html_file.exists():
+                st = html_file.stat()
+                out.append({
+                    "night_date": d.name,
+                    "view_url": f"/api/projects/{project_id}/reports/archive/{d.name}",
+                    "size_bytes": st.st_size,
+                    "generated_at": datetime.utcfromtimestamp(st.st_mtime).isoformat(),
+                })
+    return {"reports": out, "count": len(out)}
+
+
+@router.get("/archive/{night_date}", response_class=HTMLResponse)
+async def view_archived_report(project_id: str, night_date: str, db: Session = Depends(get_db)):
+    """Serve a previously generated report.html from disk (the actual artifact)."""
+    if not db.query(Project).filter_by(id=project_id).first():
+        raise HTTPException(status_code=404, detail="Project not found")
+    if not _DATE_RE.match(night_date):
+        raise HTTPException(status_code=400, detail="Invalid date (YYYY-MM-DD)")
+    safe = _parse_date(night_date, "night_date")            # also guards path traversal
+    path = Path("data/reports") / project_id / f"{safe:%Y-%m-%d}" / "report.html"
+    if not path.exists():
+        raise HTTPException(status_code=404, detail="No saved report for that date")
+    return HTMLResponse(path.read_text(encoding="utf-8"))